MARTY6565

On my 92 C4, I have a problem with the dash lights dimming down to nothing at night , when I turn on the lights, the cluster lights will stay on for a short time and then dim to black. I have replaced the dimmer, light, and traction control switch and it changed nothing. It doesn't seem like a short because it just dims down not just shuts off. Anyone have any ideas how to fix??? During the day when there is no need for lights, they stay on just fine and bright.

bwv505

it might be the sunload sensor, my 91 does the same thing, and I actually got a code for it. I believe it is the little round thing at the front center of the dash close to the windshield.

larry93lt1

Not seeing the exact problem you're describing in the manual. But . . . looks like it's pointing to the CCM, central control module, either an open or a short to ground. If you have a 92 manual I found the location of the CCM on 8A-201-9 figure 26. In short looks like the CCM is in the middle of the I/P carrier.

Check for codes ?

thedudeman321

Next to the buttons for the fuel info/gauge info/trip/reset, etc...

There's a little hole with a white sensor (a photocell) behind it. During the day cover it up so that no light gets by and see if it acts up like it would at night. That photo cell senses the amount of light in the cockpit to adjust brightness of the instrument cluster.

RollaMo-LT4

The sunload sensor your describing is used by the A/C system, not the instrument lights.


Place your finger over that sensor and you should see the light level adjust.

sailorsteve

Exactly which lights are dimming? The led and lcd lights are controlled by the ccm. The incadescent lights, which means most of them, are also controlled by a widget called the power driver that is mounted under the left side dash, just over the brake pedal. If you have the FSM, see figure 20 on page 8C-19. There is more info in Book 2, sect. 8A-117.