Instrument/Dash Illumination Issue

[medoc]

Guys,
First post here. I'm a 2001 Yukon SLT. Picked up a good, clean running one for kid at school. On way home noticed no dash lights when put headlights on. Also factory radio illumination went off (was on) with headlight switch put on. Have parking and headlights and taillights. I pulled headlight switch out. Went thru wiring diagram. Decided to bypass potential faulty dimmer by connecting Dark Green (output from dimmer) and connecting that into Thick Orange (there was a thin orange at the harness to headlight switch) which should be headlight switch output to headlight relay. On paper it made sense.
My little issue now is I might have a dash light all the time scenario. I can't tell in that I did this in driveway as I don't have access to my garage now (sunlight thing). The radio illuminates as should with switch turned on. Just reaching out before I heat shrink and button up the job.
Thanks in Advance.
Craig

 

[medoc]

Yeah Guys, I'm pretty sure the dash illumination is on all the time.
Was it the thin orange wire which is output from switch to relay ?
Or, is it that the headlight switch itself is faulted ?
If the Forum can get back to me as to which orange wire is the output line from switch to relay, that may settle the matter.

 

[medoc]

Think I know what happened here.
The only WD I had was from a Haynes manual. It is not a sophisticate enough WD to give wire gauges on the track. Going through other pages I find the other ORANGE line to the headlight switch harness is from the 10 amp fuse at the Left Bus, and it is always HOT. I pulled the fuse for tonight, and will make the change over tomorrow. Was interesting now that the sun is down, is that when engine started the headlights would be on with the switch OFF. Still could be a switch issue, but definitely a (my) wiring issue.

 

[medoc]

I should have been conventional.
Aside from my mis wiring, there still seemed to be an issue with proper switch function. Re-wired back to factory and got a new switch. All is functioning now.

 

[Ac19513]

I had a similar problem with my tahoe where the dash lights,heat/ac control lights etc would randomly go out. My problem turned out to be with the dimmer switch. if i pushed it sideways instead of rolling i could get my lights back on. I took the switch apart and cleaned to resolve. as a temp fix i stuck a penny in next to the roller to push it to the side.