headlights don't work off switch

[02YukonD]

U said 2 light sensors.. I thought these trucks only had the one light sensor (ambient).

 

[El Capitan]

So pictured is what I have on my 01 Tahoe, apparently one is a Temperature Sunload Sensor (GM Part# 15740822) and one is a Ambient Light Sensor (GM Part# 12450120) both sensors seem identical, except for the writing on the sensor itself. Now the problem I have is I do not know which sensor goes on which side, and last time I replaced them used part number 12450120 for both. Will post update as soon as possible.

 

[02YukonD]

Oh OK... I only have the ambient light sensor.. I have to pull my my dashboard apart and check

 

[El Capitan]

I have another thought anyone feel free to chime in if I am right or wrong, if the day time running lights are burnt out (both) would it cause the headlamps to come on? I have 2 new pigtails from GM for them I figure I will replace the pigtails and bulbs and see if that may be the issue.

 

[02YukonD]

I put a new ac delco headlight switch in and solved the instrument cluster lighting issue but it's still not operating the head lights.. imma go out on a limb.. but I'm driving my truck without the factory key with the chip in it. I have a regular copy of the ignition key without the chip. Maybe the computer isn't reading a chip and causing some of those problems to occur.. do that sound about rite? a could that be the issue?

 

[El Capitan]

I didn't know 02's had chips I know my 01 does not.

 

[02YukonD]

I thought they did

 

[El Capitan]

From what I understand if you have a chipped key your truck shouldn't start without a programmed chip.

 

[02YukonD]

U right I looked it up.. imma really have to pull the dashboard apart soon. My fog light not working also. Imma check the fuse and wiring with my test light

 

[El Capitan]

both fogs or just one

 

[02YukonD]

Both

 

[El Capitan]

Check fuses first, idk if there is a relay for fogs, was your truck factory equipped with fog lights?

 

[02YukonD]

OK and yes it was factory equipped

 

[El Capitan]

if fuse and relay (if there is one still unsure) are good. Try replace foglamp switch.

 

[02YukonD]

OK thx for the advice.. I'll start at the fuse and work my way back