• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

Electrical issues when wet

Kyle Dixon

New member
I have a 2004 Pontiac Grand Prix GT2 and have recently had electrical problems when it's rained and have gone through puddles. The first time it happened, I saw the lights on the dash flash and the radio turned off and back on. When I went to turn off the car, I turned the key off and pulled it out but the car was still running. I couldn't get it to shut off so I had to pull the battery cable. I left it disconnected and it seemed to reset everything.

Another problem happened to me today, I had driven it over the weekend in the rain and when I can out to it in the parking lot today, the lights were on. I tried to start it but it said the theft system was activated. I turned the key off and on a few times and it started. I left it outside and went to start it a few hours later but it wouldn't start. After trying to start, the whole electric system was flickering on and off without the key in it and under the hood I could hear the ignition relay clicking on and off quickly. I once again had to pull the battery cable and leave it disconnected to reset it all. Also, it had drained my battery so I had to get a jump.

Does anyone have any idea what it could be? Check engine light isn't on so I don't think there are any trouble codes.

Any help would be appreciated!!!
 


Some of the problems you are describing sounds like the ICM has a short somewhere. Check around the coil packs, ICM is located below, and around for anything cracked or being shorted out. Nothing else spray some water/soap mixture on the coil packs and ICM, and start the car in a dark area. If there is a short you should see an arcing effect going on.

That is where I would start first.

Some of the other things sounds like BCM too... but could be directly related to the ICM.
 
Thanks for the help negativeone13. I tried your suggestion of getting the coils and icm wet last night in the dark but didn't see any kind of arching. What happened today, I left the battery unhooked overnight so that it wouldn't be drained again. I connected the battery today and it starts right up without any sign anything is wrong. When I shut it off is when the problem occurs. As soon as I turn the key off, the dash lights back up, engine light is on, starting disabled due to security light is on and the the power door unlock sometimes doesn't work. I repeated this process several times today seeing if I could get anything to change. When I reconnect the battery, the trunk also sometimes pops open.

Does this sound more like a bcm problem because all the other power options are acting strange too? Or does the icm affect everything? I don't have time to take out the icm and go get it checked so I guess I will have to wait until I get the time to do it. Is there anyway to check the bcm? Also, can you swap those out or do you have to get a new one programmed at the dealer?

Again thanks for your expertise and on a college budget trying to avoid spending the big bucks at the dealer!
 
Back
Top