1995 bonneville - stalls and windows fail

Hello Everyone,

Well my problem isn't a new one. My bonny - will stall at about anytime and anywhere - and yes various power ckts will also fail at the same time. I have cleaned every power connection that I can find. Today I was hoping to get some replies with similar problems - Several threads here have listed answers to this problem - One guy rebuilt his starter - another person found the problem in some wiring on the drivers side of the car in some shorted wiring. Some ignition modules and or coils have been replaced (do these drop out the power rail when they fail????) Interestingly enough I did not find any threads that indicated that cleaning power connections fixed the problem - Also, no one indicated that replacing their alternator fixed the problem. One guy did replace a battery with a leaky cell - he also replaced a neutral saftey switch. I dont know which of those actions actually solved his problem. Since so many people have had a stalling problem and a power accessory problem at the same time (especially on 1994 and 95 models)- I thought it would be a good place to start a sort of clearinghouse where a collection of potential repairs could be cataloged. So if you have had a stalling and power accessory problem at the same time -What did you fix to make it better. Anyone out there want to comment???

thanks cscottyr

- and yes various power ckts will also fail at the same time.

Specifically what circuits are failing at the same time? My first thought is a ground problem as there are only a small handfull of ground points on these cars. If one were to become intermittent or faulty, it could interrupt a whole host of circuits. If your other failing devices share the same ground point, i.e. PCM ground is located under the ignition module, then this would be the most likely cause

Hey randman1,

Thanks for the input. Door locks and pwr windows are the two accessories that have failed with the system - I wasn't aware of the ground under the the ignition module until earlier today - I was going to look at that very soon.
Thanks again for the reply!
cscottyr

cscottyr, I had to do some intense troubleshooting on my 94 SSEi, but due to slightly different reasons. Only because on mine, the volt light would come on shortly before It started dieing. The way I started diagnosing was I purchased an ACTRON scantool and hooked it up, and drove around, days on end (and not too far from my home). The obvious symptom I found was the volts would slowly start decreasing (on the scantool "battery" catagory) from 14.3 at startup, to 9 volts then it would die. My GM service manuals for the car stated the PCM will power down at 9 volts. Long story short, this was with a new battery and a new replacement alternator (105 amp,...not good enough for these cars). My problem ended up being tarnished "power" connectors damn near everywhere, Power Distribution under the hood, fuse blocks, and main connector under the dash on the drivers side. One of them fixed it, just dont know exactly which? Didnt hurt to clean all of them though. When I get a chance this weekend, I'll look and see what the service manuals recommend for your problem (sorry, but tight schedule). Good luck.

Thanks jkinney for the post!

Well I found something new to think about - with the ignition on the resistance between my positive and negative rail drops to around 500 ohms - lower than it should be - Therfore - I am begining to think that I should check everything that picks up when the ignition turns on. I'll keep looking.
cscottyr

I am having the same problem, relatively speaking. My wife's 96 Bonneville has been stalling lately. It all began with problems starting (fuel pump not turning on). I noticed that when it wouldn't start, the windows and door locks wouldn't work either. I started driving the car to see if i could duplicate the problem. Well, last friday on my way to work I tried to roll down the drivers side window and the car quit. I coasted to a stop, called my wife to have her drive me into work, and figured I'd worry about it later. After work I fought with it. After a 45 minute battle it started (as near as I can figure holding down the power window switch did it) so I drove it home. When I got home, as a test I tried to roll down the driver side window again. Once again it stalled. I have read what has been written about the alternator and battery, but don't believe that is my problem. The guage is reading the high side of normal (acceptable) and the battery is good. But the symptoms are identical to the ones you have been listing. I looked at the "pigtail" to the fuse box under the hood and cleaned the connection there. This did not fix it, so I ran another wire (just in case the wire was bad) and still had no luck. My car has not been able to start since I got it home, no matter what I try, and I am completely at a loss. My wife and I both love the car and don't want to get rid of it. Does anyone have any other suggestions?

cbushnell,

I wish that I could tell you that I have it all under control and have fugured it out- unfortunately that is not the case. I sidelined my bonny mid summer to work on the house - Fortunately I had another car that I could drive. I was planning on getting back into it very soon however since the weather is turning cold quick. I have really wanted to check out the starter solenoid for some time. I dont have the schematic but am relatively sure it picks up with the ignition switch. You are lucky that your problem is always broken. If you check your positive power rail - you should see voltage lower than 9vdc. If you start disconnecting one thing after another eventually you should come to the offending ckt. Your battery could be shorting out also. - Take it to the zone and get a load test done on it. It sounds like your alternator is sound - but your battery is still in question (lso turn your lights on and see if your battery will support that.
Please let us know if you get an answer - I plan on starting to work on mine again in two weeks.
God Bless!
cscottyr

I have an appointment at a garage today, and last night rather than tow the car (just because I'm cheap :-) I tried to start it and it started... It actually started! I was able to start the car by holding down the power window button until the window actually started to go down. As soon as it did I let off and hit the key, it started right up. So, I drove it to the garage, or tried to rather. About 1/4 mile from the garage I passed under the shadow of a tree, and because it is so helpful, my car turned its own headlights on. As soon as the headlights turned on the car quit. I am convinced that it is quiting because the voltage gets too low (but my guage was still reading right around 13). I am wondering if this might be caused by a bad connection on the starter (I assume the alternator charges the battery back through the starter connection ? ) Anyhow, I will be giving all of the helpful information I have gathered here to my mechanic in hopes of it helping him and cutting down on the diagnosis time. As soon as hear his findings I will post them in hopes of it helping all the rest of you.

cbushnell

Thanks for update!

cscottyr

The garage called on thursday and told me the car needs a new fuel pump. I explained (for the 3rd) time to the mechanic that the car quits when accessories are used, but he refused to "hear". I told him to go ahead and replace it since the gas tank leaks a little and the sending unit lines are iffy (and if those are getting done, might as well do the pump too). Anyhow, I don't see where that will solve the problem unless the fuel pump is causing the short. Any thoughts before I pay this guy 600 to not fix my problem?

Hey cbushnell,

Tough question. A failed fuel pump is easy to diagnose - a pressure gauge at the fuel line and you could know very quickly. These pumps are notorious for failing - often around 80000 miles. As far as it causing your accessory voltage problem- not likely - but possible. If you are leaking around your fuel tank and have to pull it I would definitely look closely at your pump at that time - no sense in doing that job without replacing the part (knowing how often they fail). However, if I had a mechanic looking at my car - and he wasn't giving me the time of day - I would leave and go elsewhere. I think I would ask him why he thinks the fuel pump is bad - you may have more than one problem - Good luck - I wish I could offer you more help.

The garage called me back yesterday afternoon. The GM dealer sent the wrong fuel pump and sending unit. He contacted the dealer and they said the right parts would be an extra $200, for a grand total of somewhere around 850 to change the tank, sending unit, and fuel pump. I told him not to bother. It looks like I'll be doing the work myself, bu it should only cost around 400 in parts. Then, once that is done and it is still stalling on me, I can take it in again and ask that the stalling problem be diagnosed again. I'm really beginning to wonder if it is worth the hassle.

The garage called me back yesterday afternoon. The GM dealer sent the wrong fuel pump and sending unit. He contacted the dealer and they said the right parts would be an extra $200, for a grand total of somewhere around 850 to change the tank, sending unit, and fuel pump. I told him not to bother. It looks like I'll be doing the work myself, bu it should only cost around 400 in parts. Then, once that is done and it is still stalling on me, I can take it in again and ask that the stalling problem be diagnosed again. I'm really beginning to wonder if it is worth the hassle.

That's most likely NOT what's wrong with your car! I went thru the same thing last year, pump and all, they still hadn't fixed it....turns out, it was a shorted ground wire in the driver's side footwell area that was causing it to die. NOT the fuel pump I paid to have replaced! Seems the Driver's door seal had been leaking into the footwell area and had saturated a ground wire, the GM Tech found it, Spliced a new wire in and that took care of it! You are having the EXACT same symptoms I was. Everytime I would try to roll down a window or hit the Power Locks the inside lights would go out and something would make a funny crackling noise. But it would leave me dead.

Hope this helps!

MarkH
Ohio

Hey cbushnell,

Sorry about all the heartache your going through. I wouldn't pay that kind of money fo that job either. Autozone hase your sender and fuel pump for around $250.00 - you'll need a filter - maybe some lines and a tool to diconect your filter. I would buy new tank straps also. It's really not that hard of a job especially if your tank is near empty or you have a drain plug. However - before you go through all that - I would purchase a pressure gauge (aprox - $25.00) and do the following.

Turn the ignition ON; the fuel pump should run for a few seconds. Check the pump pressure for the following specifications:
1.

1987-93 vehicles, except 1993 VIN K: 41-47 psi (284-323 kPa).
2.

1993 VIN K and 1996-99 vehicles: 48-33 psi (333-376 kPa).
4.

Start the engine and allow it to idle. The fuel pressure should drop about 3-10 psi (21-69 kPa) due to the lower manifold pressure.

I tool this off the auto zone websight. Good luck - let me know how it turns out.

cscottyr

I think it may be fixed, thanks to MarkH's post. I tore the carpet and all the wires out. I found a small ground wire that had some corrosion. Fixed that, but the car still had the same problem, just not quite as bad. Further tracing lead me to a small black block approx. 2"x1" with 9 black wires running into it. They all ended up being ground wires and every one of them was severely corroded. Out of sheer frustration, I cut all the wires and rewired to the body, bypassing the block completely. I started the car (without any problems) then proceeded to run every electrical accessory that I could at the same time, and the car didn't quit.... WOOOO HOOOO. It does appear to be fixed. Once I fix the gas leaking from the sending unit (it'll be at least a week waiting for the part), I'll drive it for a while to confirm. I will post an update to let everyone know. Thanks to all who have helped.

cbushnell

cbushnell,

That is what's so great about these forums. You have access to other's knowledge and experiences and in alot of cases, it can make a huge difference. I'm getting quite tired of having my vehicle at a repair center and all they want to do is replace parts hoping the problem gets solved along the way. I'm sorry, but as a customer, I wan't a clear diagnosis, a viable solution and an estimate for repairs, NOT, we'll 1st try this, and if that didn't do it , we'll try this, and...I won't pay for that type of service. In my case it was an unneeded fuel pump. I know it would eventually need one, but I will take care of that at MY convenience, NOT theirs. Anyway, I'll stop rambling now, I'm very glad to hear your news.

MarkH

Thanks Guys for the great posts! My Bonny had a ground bus under both the drivers seat and passanger seat. After cleaning them my car no longer shuts off under heavy electrical loads - thanks for the posts!!!!!!
cscottyr

BONNEVILLE ELECTRICAL PROBLEMS/ALTERNATORS/STALLING=Poltergeist

Have blown 3 alternators. Finally went to the rebuild shop and the owner told me to replace 105 Amp crap with 140 amp Cadillac Allante alternator and install star washers at the ground points. Both alts are clocked the same=easy replacement. Also, he told me to get THE LARGEST battery one can fit in. Got 1000 cold amp battery. No more power starvation, for years.
He told me that GM 105 amp alternator is a design failure due to the non heat conducting plastic plate located over the voltage regulator. When it overheats=kills the regulator. He was v. happy and told me that thanks to the continous 105 volume he rebuilds, he was able to buy a new Predator speed boat.

As of now, 135,000 Miles later, I'm experiencing "sudden death syndrome". Car was running fine until I have replaced a sending unit. Since, it starts and stalls, or does not start on Monday, but it runs OK next day. Checked everything and I'm ready to drop the tank again. I'm sure it is a bad strainer. Also if anyone has stalling problem or charging systen shut off while turning right with less than 1/4 of a tank, check plastic baffle in the tank. They are notorious for cracks and separation from the shell. Also call dealer and ask for a copy of the TSB bulletin #92665 JUL92 Fuel-Momentary Loss of Power Hesitation on Turns.

It is fixed. My wife and I have been driving the car for about a month now without a single problem. Woo Hoo. I had a hell of a time getting the tank and such changed out, but the problem WAS the ground on the drivers side floor. If you are noticing a frequently wet floor and having a quitting problem with windows failing, check the grounds in the floor of the car. Thanks so much to all those who helped.

I've searched the web high and low to solve the IDENTICAL problem!! Sounds like cbushnell and mhollon both found and fixed the problem. Others (like me!!) have spent a fortune replacing other parts at the GUESS of their mechanic. I'm a believer, because I too have a problem with a wet floor because the windshield leaks.

My question is: Exactly where is the ground wire? I started lifting the carpet and found a puddle of standing water on the driver's side where the emergency brake cable goes into the floor. However, the floor is in perfect condition (no rust at all). There is a group of wires running in plastic conduit, with a small black block (about 3in x 1.5in x .25in) attached by electrical tape. There are several thin black wires and one thick black wire running to a piece of galvanized metal encased in this black plastic case (with a blue retaining clip) . There is some corrosion, but not very much. The passenger side has identical wiring. Are these the blocks that cause problem? How do I verify that there is a ground fault and that I've solved the problem? Of course, I could continue with the trial and error, but I figured, what the heck, might as well ask, right?

Well I've been driving the car for 8 months without any problem with it quiting. cprivitera, the thin black plastic block that you described with the numerous small black wires going into it is exactly what the problem with mine was. Mine wasn't just a little corroded, so I knew right off the bat. If it were me I'd just cut one of the thin black wires going into the block to see how black the actual wiring is. The copper in my wires was jet black for better than 2 feet. To fix it I just cut the bad wires out and soldered in new wires. I then soldered all of the new little ground wires to a battery ground cable that I had lying around and bolted that directly to the body about 1 ft off the floor (if the water gets that deep on the floor I'm scrapping the car). I only did this to the drivers side and haven't had any problems since then. The passenger side block is corroded as well, but hasn't given me any problems, so i didn't replace that one until just recently. But as long as your ripping the carpet up you might as well do both. To test it I used and ohm meter to see if I had good connection between the plastic block and a foot or so down the ground wire. I think only 1 of the 9 wires had any connectivity at all. Hope this helps.

THANKS cbushnell! This did the job for me too! When I went to test the theory, it happens that the car wouldn't start. I replaced the little "bus" bar in the plastic clip and replaced the ground wire going to the frame. The car started immediately and hasn't stalled since (only a few days so far, but it would have failed by now).

Of course, now I have a new problem. I drove the car for a few days and it ran great. Then all of a sudden it started running really rough -- like it was running on 5 cylinders. The check engine light went on so I had Autozone read the codes and it read P303 (misfire). Duh! I replaced the plugs and wires and it runs much better; however, now it hesitates a lot when accelerating! There are about a zillion sensors that could be a problem. I've read many threads about hit-or-miss sensor replacement. Cam Sensor, Crank sensors etc. Often the codes are useless or unavailable (e.g misfire). The thing that strikes me the most is that the problems that people are having are all so similar. Just like the flakey ground problem.

I'm sure that somebody has found a silver bullet to my sudden hesitation woes. Probably after dumping a fortune into non-solutions. Any ideas would be appreciated.

My car had the problem with the fuel pump quitting when I tried to use the power windows. I found the problem to be a bad ground in the driver side kick panel. I cleaned the terminal, and the problem continued. I finally decided to run a dedicated wire from the battery to the terminal. This completely cured the problem. I've had no further problems with the car stalling.

just a reminder, there is another ground on the passenger side that will most likely need to be replaced as well. that said, the hesitation you are having... does the car buck or vibrate when you are experiencing this problem? Is it usually when you are going uphill, and trying to maintain speed? When it happens, if you change you speed (step down on the gas more or let off the gas a little), does the hesitation go away? That was the symptoms of my hesitation problem. Mine turned out to be the Mass Air Flow(MAF) sensor. A little info on MAF sensors, they are what tells your car how much air is coming into the engine. So if there is a problem with it, the computer can't determine the correct fuel/air mixture. The sensor has 2 posts and metal filaments that go between the posts, kind of like a lightbulb. The filaments are wrapped in a VERY fine wire that sense the air flow. These filaments can get dirty and cause the MAF sensor to malfunction, and they can break. If you remove the sensor you will be able to see if it is dirty or broken. If it is dirty you can clean it with rubing alcohol and a q-tip, but they are very easy to break. New ones run between $150 and $250 depending on which one you have and where you get your parts. If you clean/replace the MAF you will want to change your air filter as well, since the dirt that gets on the sensor comes through the filter and it would be a shame to have to buy a $100+ part to save $10 on a filter :o)

If that is not the problem, do not look at the O2 sensors. If they are the problem, the computer will specify that telling you upstream or downstream O2 sensor. Since you said all the computer indicated was Misfire, that would not be the problem. I'll do some more research on this though. Let me know if the MAF info helps.

I have had the symptoms that you describe, though long before the latest problem. For the past year or so, the car occassionally bucks and vibrates when accelerating from a steady speed. Especially when going up hills, but sometimes on a flat as well. This problem sounds exactly like what you describe.

I cleaned the MAF Sensor with brake cleaner; though it didn't look very dirty at all. I replaced the air filter, pcv valve and fuel filter. Still no difference. The check engine light is still on and Autozone still reads the same code P0303: Cylinder 3 misfire. This might be the same code from before I changed the plugs and wires. The car seems to have all kinds of power when I hit the passing gear at about 40 or 50. In a matter of seconds, it climbs to 75mph, so I have to back down pretty quick. That kind of pickup should be there from zero mph too. It was just a few weeks ago.

Would a new MAF Sensor make a difference? It's peculiar that the code complains about a specific cylinder. That suggests a bad fuel injector or maybe the Cam Sensor. Though I doubt a bad Cam Sensor would consistently misfire on the same cylinder. Any more ideas?

are you certain you did not break one of the fine wires? If you did then the sensor is never going to work correctly. You could try resetting the computer to clear the codes and run it for a while. Before buying a new MAF sensor take a look around at the other posts on this forum to see if anyone else has any other suggestions. I know I wouldn't want to buy a $100+ part on just one persons suggestion. Also a misfire could be any number of things... maybe even a cracked head or blown head gasket. A compression test would eliminate that as a possibility. I'll keep looking as well.

I started another thread to report my misfire woes. Somebody suggested switching the coils around to see if the problem moved. My persistent P0303 - Cylinder 3 Misfire problem suddenly became a P0300 - Random Misfire. FINALLY, something that I did had an affect! That was enough for me to spend the $20 on a new coil, and voila! Problem solved. I expected a coil failure to report problems on 2 cylinders. This one didn't.

The good news is that the car is finally running good again and it only cost me about $100 for a complete tune-up. Nothing lost on this repair job! It needed a tune-up anyway. Thanks for all your help on this. I was ready to give up on this car.

Hello Everyone,

Well my problem isn't a new one. My bonny - will stall at about anytime and anywhere - and yes various power ckts will also fail at the same time. I have cleaned every power connection that I can find. Today I was hoping to get some replies with similar problems - Several threads here have listed answers to this problem - One guy rebuilt his starter - another person found the problem in some wiring on the drivers side of the car in some shorted wiring. Some ignition modules and or coils have been replaced (do these drop out the power rail when they fail????) Interestingly enough I did not find any threads that indicated that cleaning power connections fixed the problem - Also, no one indicated that replacing their alternator fixed the problem. One guy did replace a battery with a leaky cell - he also replaced a neutral saftey switch. I dont know which of those actions actually solved his problem. Since so many people have had a stalling problem and a power accessory problem at the same time (especially on 1994 and 95 models)- I thought it would be a good place to start a sort of clearinghouse where a collection of potential repairs could be cataloged. So if you have had a stalling and power accessory problem at the same time -What did you fix to make it better. Anyone out there want to comment???

thanks cscottyr I have a working solution scotty , if you are still struggling with this problem. Pull off entirely , and remove from under the hood the coil pack assembly. Under it you will most likely find a wire short that is causing your problem , it was with mine. Once this nekkid wire is no longer shorting out , you will no longer have this recurring stranded by the road recurring problem. I tried all the other suggestions I found here , but this was the ultimate cure. Also , once the drivers seat was totally removed , there was another wire short there that totally disabled my power seat adjustments . PLEASE , let me know , asap. sun. 12 / 16 / 2007

Welcome to AF, please look at the dates before posting, this thread is over 2 years old, thanks.

Hey Guys, I'm glad to see someone started a thread on these Bonnevilles. I have a 1995 Bonny that is doing the same thing, stalls & runs terrible after I hit the power window button on the drivers side. I've been trying to locate the problem, but I've gotten no where really fast. The last time this happened, I changed my fuel filter,spark plugs, & plug wires, I also noticed my plug under my coil pack was loose, I fixed or replaced everythingthat looked suspisious & that seemed to fix my problem, well untill yesterday ofcourse, Same thing happened again, I didnt get stranded on the side of the road, but it did run really rough all the way home. Once I got home I started looking for the problem once again. This time I checked for spark with a spark plug & coil tester, it showed me that my #1 & 4 cylinder are not firing, #1 & 4 cylinder run off the same coil pack, so I was thinking about replacing it, but I also know that a faulty crankshaft sensor could be giving me a bad reading, so now I'm tring to decide whether to start with just the bad coil pack & hope that works or also buy & replace the crankshaft sensor also. But then after think about it again, I'm wondering if its just a bad ground problem that I'm missing somewhere cause how can a bad coil or bad crankshaft sensor cause my power windows & door looks to stop working when these problems arise. I'm starting to believe these cars just have a bad ground problem somewhere that were all overlooking, I will be working on my car today & if I come across anything, I will post what I find, hopefully we can all get our Bonnys running tip top again soon. Thanks for sharing all your problems, site like this do help somewhat.

Hi, Bonneville warriors

Yes, corrosion is a beach on all of them. If you wandering how the water is getting in your vehicle-crawl inside your trunk and ripp off the felt trunk side lining. There is a design flaw! You will easily discover a leak ( I had both sides leaking) under the rr shelf on the either side. Water leaks behind the rr window, into a trunk and over the wheel well into a rocker panel. From there it soaks everything.

P.S. Good idea to run a 14 ga grounding wire from the transmission housing and underside of the ignition module- straight to the negative battery clamp

Hi Folks-

Many thanks for this thread! I was having the same problem with my 95 Bonneville, and was able to prove that the problem was the ground under the drivers side carpet. My symptoms were:


Car dies (fuel pump stops) anytime anywhere
Windows don't work
Door locks don't work
Rear defrost light on when doors are opened
No interior lighting
Rear defrost light on if doors closed & window or lock switches activated

Probably others too, I can't remember them all.

I don't have the symptoms for bad ground under the passenger side carpet (running bad, etc), so I haven't checked that yet.

The problem is with the "Grounding Connectors" (Page 8A-202-10 in Bonneville Service Manual book 2 of 2). The drivers side one is C340, and the passenger side one is C332.

The A wire in this connector is the one that actually goes to ground. All the rest of the wires are trying to connect to ground through the A wire. This connector is right inside the door, just underneath the carpet. It's taped with electrical tape to the large round plastic wire tunnel, and is really just a PCB connector with a big hunk of metal jammed in there to short all of the wires together (why didn't they just wire-nut all the wires together?).

When I took the plastic protective cover off of mine, everything initially looked fine. However I couldn't get connectivity to ground from any of the wires. That is, until I hit wire A. Once I touched that with my probe, a quick spark, and the interior lights came on and everything worked. The connector was pretty black compared to the other connectors. I tried to clean it with contact cleaner, but that didn't work. Then I tried scratching off the carbon with a needle, that made the connection worse. I'm currently considering simply chopping off the whole thing and using a wire nut to connect everything together.

I'm getting some more advice tomorrow and will decide then, what to do.

Thanks again!

I have a 1995 bonneville it stalled out while putting my windows down, then wouldn't start. Couldn't figure it out sent it to a shop. It ended up being a bad ground wire in the wire harness driver side floor panel. just peel the carpet back and look for corrosion clean if there and check for wire splits. Hope it helps.

Ihave read some were on here about the harness on the foot well causing major issues that is some thing to look in to

MarkH, I'm having the same problems with my 95 Bonneville but my rear defrost light will come on and my interior lights will go off. When my rear defrost light comes on my driving lights come on very dim and the engine will shut off. Did yours do the same thing?

Me again after looking more closely at what the mechanic did located where CMV described they put a self tapping screw into the metal and ran a 14 ga wire off of that and tied that into all the rest of the wires using a copper crimp same as wire nut. i did the same on the other side just cut all the wire's (ground that is) back behind the corrosion spun them all together with my fingers wrapped with e-tape and then used a heat shrink tube to ensure water won't get there again. hope it helps

no but the grounds tie into so many components its virtually limitless what can happen I'm realizing

there is a ground connection bridge under the carpet, on the drivers' side, right near the front of the door frame. pull the carpet out from under the plastic trim located beside the seat. You will find a connector with about 8 to 10 ground wires. take off the black cover. you will find a strip of metal that connects all the grounds together. pull it out. You will see corrosion on some of the terminals. clean them with a wire wheel and reassemble. These are all the major ground connections for the car. The fuel pump grounds here as well. This is what is causing your electrical problem and why your car is stalling. I discovered this while searching this site in the past. And, it was correct. It cured the troubles with the bonneville I was working on.

Sorry I know this is a really old thread but i feel its worth bumping cause it saved me a lot of time and money. I too have cured my father in-law's car with the ground connection bridge under the carpet. thanks cbushnell and MarkH, someone get them a beer.

I was able to recreate the problem by pullling one ground off at a time till i found the one that made the car stall. Mine didn't look to bad except for the "A" connection the main ground. It had started to melt the surrounding plastic and was fairly loose.

this could easy cost anyone tons of money trying to find the problem.

my car was a 96 bonneville, stalling with the windows not working after and waiting a few minutes and starting back up and running fine. and roughly 6 months apart from the last time it happened.

crazy how a connection like that would stall the car, anyone trace that wire to see what it exactly goes too?

Yes. It is the ground for the fuel pump.

For a whole year, periodically I have been going through this, 1995 bonny shuts off when I try to put my power window up.. mechanic at the shop just recently said 1st that it was the ignition lock cylinder, then it wasn't that because the previous owner must've bypassed that, so then another $75 for another diagnostic check which lead to the fuel pump... Ok, so, $664 later, I leave the shop.on a 96 degrees day, windows were down so I turned the AC on and as I was Rollin the front windows up from the drivers side panel, once again the car stalled. So now I'm wondering, if it even needed the fuel pump. It started the next day, tried to put windows up n car cut off.. then restarted over n over about 5xs..then today it started n as soon as I tried to mess with the windows it cut off again..nobody knows wut it could be.. most street mechanics are clueless n say its the battery.. but b4 I pay another shop for their guess, I am gonna check those ground wires.. I'm so greatful to have found this forum because u all have had the same problem wit the same yr car..same symptoms and everything..now hoping for the same great results...

Have the mechanic or you remove the l/s front sill plate, roll back the carpet and open the harness you will see a ground junction in that harness probably corroded by now, this must be repaired and soldered and resealed, this is the ground for the fuel pump. common issue. Same advice as the above posts.

ok, so i have another question.. could it be possible that because of this ground wire being corroded, that it just causes the fuel pump to shut down, but does that mean the fuel pump is no good??
I am just wondering if my fuel pump was even bad to begin with and not just the corroded ground wire.. HELP...!! shop wants to charge extra to fix this but i already paid way to much just to have the fuel pump put it. he said the pressure was under 40 psi so that means the pump was no good...

ok, so i have another question.. could it be possible that because of this ground wire being corroded, that it just causes the fuel pump to shut down, but does that mean the fuel pump is no good??
I am just wondering if my fuel pump was even bad to begin with and not just the corroded ground wire.. HELP...!! shop wants to charge extra to fix this but i already paid way to much just to have the fuel pump put it. he said the pressure was under 40 psi so that means the pump was no good...
If you have a marginal ground on your fuel pump and you make it worse by lowering your window (dumping more current to a bad ground), then your fuel pump will slow down/shut off. That does not mean your fuel pump is bad. Your old fuel pump was probably okay, but you just need to make sure the ground issue is fixed. The good news is, a correct repair can be verified by trying to roll down your window while the car is running and seeing that the fuel pressure remains high.

I understand :) I know this forum started years ago, but thank you so much for the quick responce... I told the shop once again about the windows making the car stall and of course, im not a mechanic so there is just no possible way i can know anything.. theyre theory was just that the fuel pump was bad, just under 40 psi, so bad fuel pump, 600$ to install new one, and hasta la vista, basically.. but the problem continued as soon as i left the shop. so i dont think it was the fuel pump at all. i think it was the bad ground caused it to shut down, and more than likely it is still good.
see the thing is that i called n had to pay for a tow so they can fix the problem, they said they did a diagnostic check and said it was the fuel pump, then when i asked to see it, there wasnt one, he just knew it was the fuel pump because it was under 40 psi wen he did the pressure check. anyhow, since he didnt fix the problem and i paid him 600$ i dont want him to re-charge me for actually fixing it this time. thats why i asked about the fuel pump, if it is necessarily bad just because something caused it to shut down.
anyhow, thanks for the quick response.

If you have a marginal ground on your fuel pump and you make it worse by lowering your window (dumping more current to a bad ground), then your fuel pump will slow down/shut off. That does not mean your fuel pump is bad. Your old fuel pump was probably okay, but you just need to make sure the ground issue is fixed. The good news is, a correct repair can be verified by trying to roll down your window while the car is running and seeing that the fuel pressure remains high. Correct, but it is possible a 18 year old pump could have been bad, but either way the shop misdiagnosed the problem and they should work with him, this is a 1.0 repair if you know what you are doing.

No..no..no, I just had the last fuel pump put in about 16 months ago.. before this one.. the mechanic I had before, thought I needed a fuel pump so he changed it n car still didn't start it ended up being the crank sensor, so that's y this time I actually sent it to the shop.. the fuel pump they just replaced wasn't old.. that's where my ? Pertaining to wondering if it was any good still came from....

Hate to say this, but if you did not touch the power window, and the car started ok, accelerated from a dead stop ok, and would cruise at 55 mph, and then you lay into it and it took off, chances are the pump was ok.....


A ground should only have like, 0.10 volts drop across it.....if the car is charging at 13.0 volts, you will have close to that 13.0 volts across that pump. less a few tenths for the ground and the electrical connections in the circuit to the pump......

However a bad ground, can create a huge voltage drop, meaning less voltage to run the pump.....it would be interesting if you had a voltmeter across that pump with the car running......compare the voltage when not using the window and when using the window.......if there is a significant difference, you know that was your problem....now fix the ground......then do a comparison of the voltages again.......

so i told the shop i sent my car too, about the ground wires, and instead he replaces the fuel pump relay. The car was fine for 3 days, drove it, and raised the windows with no problem, until yesterday I was about to go out of town and before I got to the end of my street, tried to lower the window a little and again, the car stalled, right in the middle of traffic. So I got it pushed back, looked myself for the ground wires, found them and the metal plate that they are all connected to is corroded (green, white, black) My questions are can it be cleaned? would i have to cut all the wires (i dont want to mix them up)? The guy from the shop is going to look at it again. I hope he dont think he will be charging me anymore money. When Ive told them before what to look for. If they don't do it, I want to know if I can clean it or buy one from the dealer???

If you have found the bad ground point, the problem is nearly solved. Depending on how thick the metal plate is, you can disconnect the wire that is attached to it and then take a wire brush attachment for a drill and buff the metal so that it is shiny and new looking. Then you strip the wire, or wires, that were connected there back and stick them in a thing like what is shown, solder them in and then drill a hole into the ground point (a solid metal point ) and stick a sheet metal screw in there and crank it down. Then take some grease and coat the hole area. This will be good for a few years. If that ground point is not good enough, choose another. You may need to get some large gauge wire to take you over to it, but the process is the same. Make sure that you do not drill into anything important.

well im not sure if its the bad ground point. all the wires look good, tightly soldered and the plate is thin, not thick..but the whole plate is corroded. i tried scraping some off, but what i was wondering if cleaning it would be better than trying to get that part from a dealer, i know it would be cheaper, but to get into the small area where the wires go with a brush will be kinda hard. unless the plate comes out, do you know if that medal plate comes out.? Im sorry just dont have much money, and know knowledge of cars.. i dont want to do it wrong, by mixing any wires up, by removing them..

You should cut out that soldered splice in the harness clean up the grounds in the splice and resolder all and use shrink tube and some way to seal up the junction.

Ok so the mechanic from this shop.came to get the car said they think it might b a bad fuel pump the put in and the ground wires don't have anything to do with this..I told them over n over about the grounds, its plain to c its all corroded, how is the fuel pump going to cause the windows n locks to make the car stall.. its clear that's its electric.. Idk, I paid way topmuch for a FUEL PUMP they said costed them $350 wen its only $72.99 at auto zone so I know they gtta probbley have a contract to get parts cheap.. I contacted the bbb hopin they can help me either fix the problem I paid already for, or give me some of my money back so I can go somewhere else. Period. If I wanted bullshit guesses I would've went to someone on the streets wit barely any tools.

Well, it's painfully obvious, if you replace a fuel pump, and a relay, and the
EXACT same symptom, is there, it didn't fix the problem.....

WHAT KIND OF GARAGE IS THIS? It obviously was not a GM shop, or a high end chain.....If it was a GM shop, shame on them....

You told them about a possible ground problem....which they seemed to poo-poo.....

Ok so the mechanic from this shop.came to get the car said they think it might b a bad fuel pump the put in and the ground wires don't have anything to do with this..

I have access to a '96 manual....in it, G202 is the ground for the master power window switch....G202 is also the ground for the fuel pump......a ground problem here could potentially cause your problem.....G202 is located behind the kick panel in the E-brake area....

Complaining to BBB might not get your money back, but if this shop gets enough complaints from BBB, changes will have to be made if they want to stay in business....

I don't know how anyone in their right mind would think that if you try to roll your window down and your fuel pump stops, that it is a bad fuel pump. I would think the conclusion would be that the window motor was bad.:runaround: Sorry.

we have seen a lot of these issues with the H bodies... More than most of the time its due to the ground buses getting wet and corroded... There are ground buses on both sides of the car, drivers side ahead and to the left of the seat under the carpet, and on the passenger side ahead of the seat and to the right under the carpet... These Ground Buses are the grounds for a series of different items, if they get wet and corroded they will cause a battery of problems, windows quitting are a dead give away... Clean those grounds, most likely that will be the solution...

More than likely, they have been corroded by a water leak....when you remove that door sill trim, and lift up the carpet, you might be surprised how wet it is under there.....because of the rubber backing on the carpet, it will only seep through if the leak is real bad.....otherwise, the jute backing just gets soaked and corrdes the grounds.....

Can't tell you the numbers of SDM's and harnesses to the SDM's that I have replaced due to this.....GM had it on the floor under the PS seat....later the relocated it to the hump in the middle...

When you find water under there, you basically have to remove the interior of the car to get the carpet out to dry.....then wet down the car to find and repair the leak(body seams and water deflectors in doors seem to be the main culprits)......and then this is the time to check all those grounds that are exposed, and any harness connections, before reinstalling the carpet.......

I just wanted to thank everyone for their input. I just started having this problem with the car stalling when I simply touch the window switch. My mechanic friend had already figured that it was a ground problem and now we know exactly what the problem is--other than me buying this 20 year old car. It was interesting to read about your problem with a 9-year old car just 12 years ago. I have a 97 model. I really admire and appreciate all of you that know your way around these cars.

Well I found something new to think about - with the ignition on the resistance between my positive and negative rail drops to around 500 ohms - lower than it should be - Therfore - I am begining to think that I should check everything that picks up when the ignition turns on. I'll keep looking.
cscottyr
Thanks for all of the good info. I just bought a 97 model and started to have the same problem after my friend had worked on it for a month in his spare time.
This is going to save him some time.