Electrical issues! Need help ASAP!!! 02 Denali
bull5169
09-07-2008, 10:36 AM
Hello all,
Here are my problems, which seem to be electrical.
About 9 months ago, I noticed that my rear wipers would jump when I turned my foglights on. I researched and found info regarding problems with the foglight switch and the "ground issue" with the rear washer fluid pump. I changed the switch, and did the ground issue workaround for the wiper. This did not work. I also noticed that about the same time, my abs light and the brake light would come on occassionally. Then my dash blinker indicators would light up very dimmly, not on or full bright, just like a slight glow. So I then disconnected the ground for the wiper pump (fixed the wiper jump, but left the rear washer pump disabled). The abs and brake lights did not come on for some time, but the dash indicator lights did the glow thing very regularly. I then researched some more and found some mention of the grounds that are on the chassis and how they can cause problems. I was unable to find anyone who could actually pinpoint to me the ground locations, so I did not really do anything with this theory. Since I had no real issues (car stalling or lights not working), I kind of forgot about the problem.
BUT......last night, a whole new chapter!!! Last night my car did some very, very weird stuff. I had come out of a friends house and started my truck. It started fine, then all of a sudden it just died. I did notice that the abs and brake light had come on just before the car actually shut off (maybe 30 seconds). I restarted, pulled out onto the street and the car died again. I thought that since my low fuel light had just come on, and I was on a slight incline, that the fuel may have be the issue. So as it died a third time I sat on the side of the road for a few minutes, trying to start all the while, but nothing. It just cranked and cranked. Then finally, it started and I got rolling for 10 feet then it died again. Luckily, the gas station was right there literally. I got into the station, added some fuel, and tried to restart. No luck. Then after about 10 minutes it started. I drove it 30feet then it died. I ended up calling for a tow, and while I waited I noticed these weird happenings.
My rear turn signals would not blink when I turned the hazards on. the rear brake light was blinking instead
my front turn signals were very dim
sometimes the key-in-ignition chime would sound, and sometimes not.
Then, as I sat still waiting for the tow, it dawned on me that the truck initially stalled as soon as I turned on my foglights!! So, I then started the truck up, let it run for a good 5 minutes, then I hit the foglight. Whamo! the truck stalled, and would not restart for 3 minutes. I got it back running, then the tow came. Once I got back home and unloaded the truck, I started the car, and parked it. No problems.
Forward to Next morning: I go out to my truck, start it up and let it run. check fuel flow by gassing throttle. looking for sputtering or hesitation. Nothing unusual. Then, I hit the foglight. BOOM! Dead again! But this time, the car restarts immediately and continues to run. So, I go to the dealer for advice. One of the techs suspects the altenator (i also suspected the voltage regulater, given my past quirks with the dash lights). I leave there, grab a new battery, just in case, and head home to replace that. I can not replace the alternator today because of the bad weather. But, I have started, restarted, and restarted the car over again over the course of the day. No issues, even with the fog light!
Forward to today: I get in the truck, start her up and take of to work. All seems fine until 1/4 mile later. BOOM, it dies! I coast off the road into a parking lot. Crank, crank and crank, until finally it starts, but not for long. I try again, and it thankfully stayed running for me to get home. I sit infront of my house debating on taking a chance at getting to work. Oh hell, why not. Its sunday and no traffic. I hit the highway and fortunately make it to work without a hitch.
So here I am! At work ready to tackle this beast. Now I need some advice and help on this. Can anyone give me some insight as to where I should begin? Before that, can you guys tell me
where the chassis grounds are
what could be the cause of the quirky electrical issue
Thanks way in advance.
Here are my problems, which seem to be electrical.
About 9 months ago, I noticed that my rear wipers would jump when I turned my foglights on. I researched and found info regarding problems with the foglight switch and the "ground issue" with the rear washer fluid pump. I changed the switch, and did the ground issue workaround for the wiper. This did not work. I also noticed that about the same time, my abs light and the brake light would come on occassionally. Then my dash blinker indicators would light up very dimmly, not on or full bright, just like a slight glow. So I then disconnected the ground for the wiper pump (fixed the wiper jump, but left the rear washer pump disabled). The abs and brake lights did not come on for some time, but the dash indicator lights did the glow thing very regularly. I then researched some more and found some mention of the grounds that are on the chassis and how they can cause problems. I was unable to find anyone who could actually pinpoint to me the ground locations, so I did not really do anything with this theory. Since I had no real issues (car stalling or lights not working), I kind of forgot about the problem.
BUT......last night, a whole new chapter!!! Last night my car did some very, very weird stuff. I had come out of a friends house and started my truck. It started fine, then all of a sudden it just died. I did notice that the abs and brake light had come on just before the car actually shut off (maybe 30 seconds). I restarted, pulled out onto the street and the car died again. I thought that since my low fuel light had just come on, and I was on a slight incline, that the fuel may have be the issue. So as it died a third time I sat on the side of the road for a few minutes, trying to start all the while, but nothing. It just cranked and cranked. Then finally, it started and I got rolling for 10 feet then it died again. Luckily, the gas station was right there literally. I got into the station, added some fuel, and tried to restart. No luck. Then after about 10 minutes it started. I drove it 30feet then it died. I ended up calling for a tow, and while I waited I noticed these weird happenings.
My rear turn signals would not blink when I turned the hazards on. the rear brake light was blinking instead
my front turn signals were very dim
sometimes the key-in-ignition chime would sound, and sometimes not.
Then, as I sat still waiting for the tow, it dawned on me that the truck initially stalled as soon as I turned on my foglights!! So, I then started the truck up, let it run for a good 5 minutes, then I hit the foglight. Whamo! the truck stalled, and would not restart for 3 minutes. I got it back running, then the tow came. Once I got back home and unloaded the truck, I started the car, and parked it. No problems.
Forward to Next morning: I go out to my truck, start it up and let it run. check fuel flow by gassing throttle. looking for sputtering or hesitation. Nothing unusual. Then, I hit the foglight. BOOM! Dead again! But this time, the car restarts immediately and continues to run. So, I go to the dealer for advice. One of the techs suspects the altenator (i also suspected the voltage regulater, given my past quirks with the dash lights). I leave there, grab a new battery, just in case, and head home to replace that. I can not replace the alternator today because of the bad weather. But, I have started, restarted, and restarted the car over again over the course of the day. No issues, even with the fog light!
Forward to today: I get in the truck, start her up and take of to work. All seems fine until 1/4 mile later. BOOM, it dies! I coast off the road into a parking lot. Crank, crank and crank, until finally it starts, but not for long. I try again, and it thankfully stayed running for me to get home. I sit infront of my house debating on taking a chance at getting to work. Oh hell, why not. Its sunday and no traffic. I hit the highway and fortunately make it to work without a hitch.
So here I am! At work ready to tackle this beast. Now I need some advice and help on this. Can anyone give me some insight as to where I should begin? Before that, can you guys tell me
where the chassis grounds are
what could be the cause of the quirky electrical issue
Thanks way in advance.
bull5169
09-08-2008, 11:59 AM
UPDATE!
I ended up having the altenator bench tested, and it was fine. I went ahead and changed out my belts for gp. I though all was good last night as I tried to recreate the problem so I could do a systematic troubleshoot. I could not recreate the problem last night. So I thought that the belts may have been the issue, or there may have been a bad connection at the altenator that I corrected once I removed and reinstalled it.
This morning I start the car, and just to verify that the problem was gone, I hit the fog light button. Damn! the car stalls. It wont restart and all the gobblins return. The flashers, the dash lights, etc. So I begin to remove fuses, relays, and such, but nothing I disconnect will allow the car to start. Sounds like the fuel pump loses power when this issue arises. Eventually, I decide to disconnect the battery to see if something was tripped and maybe this will reset it. Bingo, the car starts normally once the battery is reconnected. It takes about 30 seconds of waiting, but it fires up fine. I hit the fogs again, and the car stalls. Same problem again. I disconnect the battery, and the car starts fine again. SO I have narrowed it down to either the foglights, or the circuit that they are on. I am assuming that the fogs are on the same circuit as the fuel pump.
Now my question is whether the BCM may have something to do with this mess.
Any suggestions?
I ended up having the altenator bench tested, and it was fine. I went ahead and changed out my belts for gp. I though all was good last night as I tried to recreate the problem so I could do a systematic troubleshoot. I could not recreate the problem last night. So I thought that the belts may have been the issue, or there may have been a bad connection at the altenator that I corrected once I removed and reinstalled it.
This morning I start the car, and just to verify that the problem was gone, I hit the fog light button. Damn! the car stalls. It wont restart and all the gobblins return. The flashers, the dash lights, etc. So I begin to remove fuses, relays, and such, but nothing I disconnect will allow the car to start. Sounds like the fuel pump loses power when this issue arises. Eventually, I decide to disconnect the battery to see if something was tripped and maybe this will reset it. Bingo, the car starts normally once the battery is reconnected. It takes about 30 seconds of waiting, but it fires up fine. I hit the fogs again, and the car stalls. Same problem again. I disconnect the battery, and the car starts fine again. SO I have narrowed it down to either the foglights, or the circuit that they are on. I am assuming that the fogs are on the same circuit as the fuel pump.
Now my question is whether the BCM may have something to do with this mess.
Any suggestions?
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