Hi guys, some more diagnostic help needed here. I know that I already have some issues with the BCM accessory power retention feature, but I am also having some other electrical gremlins. First, I never know when the turn signals are going to work. More frequently the right signal will display a constant light when the switch is activated, but sometimes the left will do this. No way to predict when this will happen, this is purely random. Wet or dry, it doesn't matter. Most of the time they both work perfectly.
Second, when the headlights come on the dash lights will go out including the odometer, except for the idiot lights I'm currently seeing (low coolant and SES). Dosen't matter if it's with the automatic on feature or with the manual switch. Could this mean my BCM is going completely t!ts up? And what would happen if a total BCM failure occours? Thanks in advance!
J.B.

 

both problems are not related to the BCM


turn signal issue might be a problem with the switch, more diag is needed

and what do you mean the dash lights go out when the head lights come on? are they on when the headlights are off?

 

He probably means that dash lights come on only when fog lights are on, and go off when head lights are turned on.

He could also mean that dash lights do not come on at all

 

The dash backlighting works fine when the car is in the garage and the parking brake is set and the car is running. Releasing the handle to full down position activates the auto headlights and at the exact moment the headlights come on, the dash backlighting and radio/clock lights disappear. Same thing happens when I turn the headlights on with the dash switch. Does this help any?

 

Check the grounds, they are feeding back. Danny Mc