When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Couple of nights ago we had a massive rain and a drain close to where I was parked was clogged up. I'm not sure if that's how water got in or if it leaked from the top somewhere. Haven't had any issues before with leaking.
When I got off work the battery was drained so I jumped it and it was running fine. Interior lights were shorting. Immediately went and dried out the floorboards.
My issue now is there is a massive power drain (10+amps). I've tried pulling fuses/relays and I can't seem to pinpoint it. I also have electric seats disconnected. I had no codes when I was driving it around yesterday. It's hard to even diagnose the thing as the battery drains so fast.
Yeah water most certainly got in there. It was dried out but it's what happened after that. Yesterday I was out working on it with a fully charged battery and I wasn't getting any drop in voltage. It fired up and ran fine so I checked it a few times before work and the battery was holding voltage. Thought she was all dried out and all was good. Then just as I'm leaving for work I turn the key and nothing. Battery still had voltage but it refused to start and the interior lights weren't coming on with the door. Dash lights and door chime all still worked though. So today after work I took the BCM out and cleaned it with 91% isopropyl and a tooth brush. Everything seems like it's back to normal now so fingers crossed.
Looks like I spoke too soon again. After the car goes to sleep it doesn't wake up and it takes resetting the power to the BCM to wake it up. I talked to the dealership today and the service manager said they are too busy to work on vintage vehicles lol. I've been reading a lot on the topic but I keep seeing different things and much of it is pretty old information. My question now is can I pick up another BCM from rockauto or GM Parts Direct and also pick up a Tech2 and take care of it myself?
Try cleaning it again making sure there's no corrosion or salty deposits or any crud at all on the board that could be bridging or shorting out any of the contacts, like shown in that pic of your BCM above. It has to be spotless, both sides.
I tried cleaning it again. My iron is in rough shape and I pretty much only use it for speaker crossovers. I'll have to pick up a more suitable one for re-flowing.
I dropped in a re-man BCM from RockAuto, did the re-learn, and went for a drive today. Security and air bag light stay on. Other than that all seems good for now. If I did pick up a Tech2 would I be able to take care of the rest?
Also is there a way to rename the thread to something a little more suited so others might stumble across it with similar issues?
I'm not experiencing the power drain with the new BCM. However after cleaning the old BCM the drain had gone away. I've been driving it mostly without issues with the new BCM however today it refused to start and I had to reset the power to the BCM to get it to fire.
With the old BCM the interior lights wouldn't come on when I opened the door. For a while I could reset the power and they would come on and the car would start. Today the interior lights did come on and everything seemed normal but it didn't want to start. The security light was also not lit. I feel like I'm going to be tracking down issues for a bit.
Quick edit. Just went out and the interior lights didn't come on again. Could something be killing the BCM?
Huge power drain :(
