1995 bonneville - stalls and windows fail

[Tonedog]

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.

[MRDANGERUS]

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

[cmv]

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:

1. Car dies (fuel pump stops) anytime anywhere
2. Windows don't work
3. Door locks don't work
4. Rear defrost light on when doors are opened
5. No interior lighting
6. 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!

[stracer4life83]

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.

[big white bufflo]

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

[BigJT]

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?

[stracer4life83]

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

[stracer4life83]

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

[clutch492]

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.

[Your_Mom]

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?

[clutch492]

Yes. It is the ground for the fuel pump.

[cmgarza]

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...

[maxwedge]

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.

[cmgarza]

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...

[rkvons]

Originally Posted by cmgarza

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.