I'm about to do some troubleshooting, but I drove to the store and I had no headlights.

Start the car up, DRL come on. Turn it to the running light position, and it's working fine. Turn it to the on position, and the head lights go out! The running lights say lit. What gives? I ended up driving to the store with the running lights on and the DRL on.

What I have done over the last week was install a remote start. I tapped into the running lights, but not the head lights. When I took the dash face off, I did have problems with the plug for the light switch. I started trouble shooting there.

I rebuilt the switch. I tore it apart, cleaned the contacts, used di-electric grease on the contact points and put it back together.

This didn't help. As soon as I turn on the switch to the headlights on position, the DRL turn off and the headlights do not come on.

Under the dash is a relay, I pulled the relay and the DRL don't come on. That relay works 100%. I can't seem to find the relay for the headlights. I did not find a fuse for the headlights (by themselves), only for Lighting. Fuse is good, even tested it with a multimeter.

Tried to activate the high beams. They don't flicker on at all.

Ideas?

Hardwarz[/align][/align]

 

I have the same problem only with a '98 4x4. I have done all of the same checks including the purchase if a new switch $70 bucks next, hope they will take it back or swap . Same problem with the new switch.
Help ! all I have left to drive is a diesel and it does not get great milege and you know the price per gal.

 

You'll have a fuse labeled HDLP, check it. I have burned a couple of thosefuses in our 99 Burb.

 

On my 99 'ho, it turns out the problem was mine. I added in a T harness for the remote start. There's a bolt that holds the 2 parts of the harness together so they don't come apart. I had one side bolted good, the other side was not bolted that good. the bolt was actually keeping part of the harness apart enough so that the lights wouldn't work unless I played with the harness.

So, my problem was caused by me 100%.

My suggestion... check the ignition harness under your dash. Make sure it's not loose as this would cause the same problem.

 

Hey, Hardwarz, This is right from a friend that had the exact problem and he found it in the steering column at the dimmer switch. He pulled the covers off from around the tilt and said it was in the plug-in for the dimmerswitch and it was a little of a bear to get to. The cruise control wires are next to it and are 24ga. at least. The wires that controlled the bright and dims had pulled loose or broken due to the nine years of flexing. I'll have to try when I get home to see if this is my problem. This guy is pretty honest, I believe I can trust him.Good luck!!!!

 

I Have 97 tahoe that had same symptoms. Came back to life by simply operating dimmer switch. Must have been in limbo somehow. Didn't have to take apart steering column.

 

I'm haveing the same problem with my 99 tahoe, i have canged the switch and relay, that didnt do anything. i'm gonna try the wires around the dimmer next. i will let everyone know how it turns out.

 

99 GMC suburban with headlight problem. Look at the harness that's for the multifunction turn signals, four-way and ignition system. it's all one unit the harness has a bad connection and if you move it around enough you will see the headlights flashing on and off.

This video on how to replace that unit will help you identify the connections I'm speaking of. I replaced that unit it's a real pain in the butt, but it can be done there are other videos that show how to do it without removing the steering wheel.

I replaced it because my turn signals in four ways were malfunctioning but then I had headlight issues with the replacement part. I fixed it by jostling those wires and wedging a piece of wood to hold the wire to make a good connection.

This will fix the problem if you haven't already.
Franklyn