Unusual Electrical Problem - Multi problems on 2002 Century.

[pmguire]

A couple days ago, I went to drive my car and clicked on the remote and noticed Back and front lights did not come on as usual but door did unlock. Upon entering car I heard buzzer go that indicates lights have been left on. But the lights were not on. Checked other things and noticed back lights weren't working when switch pulled on. But brake and signal lights were still working properly. Also, the twilight automatic on for headlights feature has quit as well. Also, there is no illumination in the instrument cluster area which should illuminate when headlamps are turned on. Checked most of the basic things. I replaced all bulbs in the back and checked fuses. Any suggestions or help would be appreciated.

 

[ryenie]

First thing that comes to mind is the lighting control module, but you don't seem to have one. Theres a turn signal\hazzard module, and a drl module, otherwise the rest of the lights are controlled by the body control module. Could be loose corroded connections at the bcm, or a bad ground connection somewhere in the cab. Might also be a solar sensor, but the manual controls should override that. There's a good chance that there are codes stored in one of the modules that could help isolate the problem but the only scanner that comes to mind is a tech II scanner which is, for the most part, a dealership scanner. It would need to read b (body), and u(undefined, usually module related) codes and possibly c (chassis) codes. Typical scanners only read p (powertrain) codes, and the code you would need would not be found in those set of codes. It would most likely be a b code. It could also maybe be the dimmer switch. The lights may not have flashed because the bcm detected a malfunction in one of the lighting circuits.? Sorry to throw all that at once, but should give you some sort of starting point.