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1996 Coupe. I don’t have lights on any buttons or switches when my headlights are on. The dimmer does change the brightness of the instrument cluster and radio/HVAC and the interior lights come on if I slide it all the way up.
Last edited by CE_Vetteboy; Aug 6, 2021 at 12:03 AM.
Checked all the fuses they all look fine. I searched the forum and google but this seems to be an unusual problem as I’ve found nothing that resembles the same issue. Could the photocell on the dash have any influence?
Using the paper clip method I checked the CCM for codes (none) and tested the dimmer circuit including the ambient sensor involvement, all seems to be functional. I tested the courtesy light output, I can hear the relay and the interior lights turn on and off. The problem is I isolated to the LED side of the lighting circuit as all of the incandescent lights work but none of the LED’s (buttons, switches, power window switch and lock illumination,etc) are working. Since my FSM hasn’t arrived yet I found a few diagrams of the dash wiring on here. I would like to test the incandescent power driver as I do not have power to the three fuses (RH ILLUM, LH ILLUM and CNSL ILLUM) anyone know where this module is located?
Well I couldn’t wait until tomorrow it was bugging me so I tore into it. Located the module and tested it as per the thread I attached in my last post. Sure enough I had reference voltage, input voltage but nothing on the output. I removed the module and placed a jumper between the reference and output wires and bingo! We have lights.
Well, I installed the replacement module (non-GM) and it did not work. Testing the output gave me 0.0 Volts right out of the box.
Again, if I jumper 12v to the output wires, all of the lights work. This tells me everything downstream of the module is good (grounds, etc).
I have now ordered a new Delco unit and will report my findings once I have it.
Sometimes the aftermarket electronics do not work well in our cars. I can't tell you why but it really seems to be hit or miss. Keep us updated on how things turn out!
Glad to hear that its back up and working properly! Shame that its a made in Mexico part in a Delco box. Part of the reason I loved these cars so much was because their replacement parts were made in the U.S. Now it seems there's more and more outsourcing going on. At the end of the day it works and hopefully will give you no similar trouble in the future.
Dash light issues
