headlights and dash lights

when i crank up my car the dashlights come on. but when i turn on my headlights the dash lights cut off... does anyone have a solution to this?

Has the car been wrecked or had any electrical components installed recently?

My buddy wrecked his Z71 Yukon, Smashed the front up good, although running again, when he turns on his headlights his dash lights and taillights take about a minute to come on... havent figured it out yet, but his stereo system has been cutting out recently too, sound comes in and out...
gonna check for a disconnected or bad ground.

do they come on when you put your parking lights on though, and then cut off when you flip the rest of the way over to headlights?

is it just your dash lights or your gauge and warning lights too?

I always tend to have more questions than answers...
Hope to see you post again soon, good luck!

I replaced a radio for a friend who's car got jacked of their former radio once. In all the confusion of figuring out which wire was what, I left the ground open and hooked an accessory wire up as ground (by ground i mean neutral) so when the accs. wasn't in use, it held a ground, turned the lights on it was hot, which killed both the lights and radio until the switch was back off. (i don't exactly understand it, but it worked fine once i corredted the radio wiring)

All that is to say, sounds like a wire is crossed, or loose/broken, in both your cases. Tho, Amy, It is possible you need only to turn up the brightness on your dash, as i think they dim automatically when the lights come on...

Yeah, i mentioned that I was already going to check for a bad or disconnected ground... but thanks for confirming my suggestion,

In fact, while doing repairs on his truck we took off at least 3 ground wires which have now mysteriously dissapeared... relatedly we also took off his fog lights and KC Daylighters, so we believe that the grounds we disconnected were wired up to those, but we'll keep looking to fix his taillight delay...

Also the stereo sound cutting out I beleve is related to one of his amps, bad connection (I tapped on the wires the sound came in and out)...

It may be because he is running 10 gauge where he should be running 8 gauge (my suggestion), or at least 4 gauge (recommended by tweeters-think they just wanted to charge him more though)

Anyone think that this may be the cause or know what symptoms this would cause (burned wires, blown fuse, etc.)?

While I'm not a mechanic, I am an electrician. That said, i don't know nothing about dc stuff. But in old houses, burned up grounds from using bigger fuses while leaving the smaller wires is very common. maybe someone else could be of more help...

glad to see we have an electrician in the house! don't underestimate yourself.

well my buddy's yukon's stereo system is working perfectly again... It was a bad ground on one of his amps, went out with a multimeter to check voltages during the problem and find a good place to ground out a temporary wire, blew a fuse (oops), but replaced it and rewired a temporary ground to fix the problem. All is going well so far but didn't check to see if this fixed his light problem, I will repost when I see him again.

haha! thanks. hope the lights turn out well.