Loosing shift indicator and radio displays in daytime

[mckpaul]

2002 Impala. Normally, in the daytime, the headlights go off, the running lights come on, the dash illumination goes out, and the shift indicator and radio displays go to full brightness. At night the headlights and dash illumination come on, and the shift indicator and radio displays switch to whatever the dimmer control is set to for the dash brightness.

Now, the parking light indicator stays on all the time as if the parking brake is depresses (have been under the dash and physically checked the switch and wiring, all is well there). There is an LED on the radio that normally blinks when the car is parked, and used to be off when the car was running, it now stays on all the time. In the daytime, the headlights and dash illumination switch off like they should and the running lights come on, but the shift indicator and radio displays go off too. Radio still plays fine, just no display. At night, the running lights go off and the headlights and dash illumination come on, and the radio and shift indicator come on in the dimmer controlled mode. Also, there is no high beam indicator light.

At first the problem was inttermittent, when I started the car, if the parking break indicator went off, I knew everything would be fine. Now it's always in the messed up mode. The car runs fine, not causing any real problems except not being able to see the radio display ( I can pull the headlight switch out and see the display if I really want to know what station I'm on, but it's not full brightness as daytime mode would be)

Was wondering if anyone else had screwy problems like this and what they did to correct it.

[bermis519]

My impala does the same this as far as the radio display goes. When the head lights come on, the display disappears. I started messing with switches and knobs. I finally figured out on the headlight switch. When you twist the know to make the display brighter/dimmer. If you tweek it right the radio display will come back on. I haven't done anything about because i just live it. I was told that you have to replace the headlight control thing and it will be fine.

let me know
mike

[mckpaul]

At last! A Reply!
I read somewhere that the different control modules communicate with each other with serial communications. Also read that sometimes they loose communications from bad connections in the multi-pin connectors where the wiring harness connects. Read that quite often weird problems can be solved by unplugging and re-plugging the connectors making sure they are all seated completely. I plan to get under the dash and do this on all the modules I can find. The body control module on mine is under the dash just behind the headlight switch and has three big plugs on one end with a BUNCH of wires on each one. Further research tells me most of the lights and indicators I'm having problems with go to the body control module. Hopefully the re-plug process will solve my problem, but I have my doubts. I'll post my results when I do it, maybe this weekend.