The displays (gear selector, odometer, radio, overhead console) always go dim whenever I start-up the engine. If I press the dome light over-ride button four times to shut off the daytime running lights, I get full brightness back.
I measured the resistance of the sunload or light sensor in the dash right speaker grill and found that it was not changing with light level, so I replaced it. New one does change, but displays still go dim in full sun....

Anyone else's do this? I finally put a resistor across the sun load sensor terminals so that the it appears to be in full sun all the time. No more display dimming, but would like to know what is really wrong here.

Thanks,

 

what resistor value did you use?

 

I think I used a 500k or so.

 

ok thanks, i have the same problem and i would like to diable it

 

Correction....I used a 1K ohm resistor. I tried shorting the pins out...nope....tried leaving the connector disconnected from the sun sensor...nope.....but a 1K ohm works just fine.

So yours is doing the samething huh....interesting.

I also found out the the light sensor puts out about 0.45Vdc in full sun...so it is not just a change in resistance. There is 5Vdc across the connector as well.

I put the 1K ohm back in, put electrical tape over it and am finished with trying to get this thing to work any different. I have full brightness on my displays so I can see them!

Good luck with yours.

 

Thanks for the corrected info
tonight ill run out to radio shack and buy the pack of resistors.
I don't think they sell them seperatly any more.
Barrett

 

Unless I'm misunderstanding your situation, there is no problem with your displays. The DRLs come on when you start the engine and the dash lights dim just as they would at night due to the auto headlight feature. I just turn off the DRLs with the dome override button and drive away. All perfectly normal.

 

Trouble is the displays would dim and I could not see them. I got tired of always having to press the dome control button 4 times to turn off the DRL and bring the displays back up. Now with the resistor in place, I have full brightness on the displays and I have DRL on.

I believe the auto headlight feature is supposed to bring the headlights on and dim the displays when dark...according to the light/sun load sensor input. But they were always dimming...and in full sun I could not see either the overhead console display nor the gear seletor or odo/trip.

Something is wrong somewhere in the circuit....but have no schematic. I assume it is in the body control module, but I am done with this. I can remember to turn the headlights on when dark...at least for now.

 

Sorry, I just don't see the problem with your system. Your owner's maual explains the operation of the auto headlight and DRL systems. If you don't have one, register your VIN with GM Owners Center and you can view the manual online.