Okay, I'm posting this for my dad, so bear with me.

He has a 1997 Z71, and his daytime running lamps work fine when his headlights are turned off. However, if he turns on his headlights at night or early morning, both his daytime running lights and low beams (I'm not sure about tail lights) stop working. If that happens, the only way that he has headlights is by using his high beams. This is not a continuous problem. He was going to take it to the shop, but it started working, then it stopped, and he took it to a friends, but couldn't get it to do it again.

I know that he has checked the fuses. I do not know what else he has checked.

Any ideas??

 

The first place I would look is at the headlight switch itself. Might be making a bad connection at times. I am not sure but those switches might be able to be taken apart and cleaned. Good luck!

 

Shamrock is right...to a point (sorry shamrock) But I had this same issue on my suburban and it ended up being the multifunction switch which had the brown wire half melted off (chevrolet really needed to use better wire) I ended up resoldering the wire on and replacing the headlight switch.......My money is on the multifunction switch. *****Warning**** If you do decide to "dig" into the steering column to look at the multifunction switch BE CAREFUL you CAN set off the air bag if you do something wrong. It is best to unhook the battery before ANY electrical work. but this will NOT prevent the air bag from going off (seen it happen).

 

Please don't apologize. I, by no means, claim to know it all. I personally have never had this particular issue and figured it would be a logical place to start. I can see where the multifunction switch which controls the high and low beam setting could be the culprit as well. Thanks for sharing the knowledge. Just to clarify for the original poster the multifunction switch is the turn signal switch that runs through the steering column. Good luck and let us know what you find.

 

No Problem Shamrock (just being nice lol)