I have 2003 Monte SS that I used to love. However, in the past year the trunk started popping open for no apparent reason and the headlights started flashing (sometimes in the night when we we in bed so it wasn't us). Then the Engine Light started staying on all the time. I was told it was the Gas Cap got a new one but didn't help. Then the rear defroster (and outside mirror defrost) quit completely. The last thing to go is I think the BCM, be all of my interior lights went totally dim. You can't see them in the daylight at all. (Includes the roof thing with the temp and mileage)....My radio plays music, but It resets itself by anywhere from 20 minutes to 5 hours everytime I start the car. I just put a new battery in it and I keep a battery tender on it (If the battery tender isn't on the car it won't crank within days). I took it to 2 mechanics, including a Chevy service center...an NO ONE can fix it. To be fair the Chevy guy "fixed" the BCM but it only partially worked (stilled had all kids of error messages) but it reverted back to it's totally broken state in 1 day. I don't know where to look next. Any ideas?

 

Probably a short somewhere..

Maby a whole new computer system would fix it