Happy Holidays everyone,
Senario: got in my 98 turned the headlight stalk no headlights up or on checked every fuse all appear good all other lights work including fog lights. Today I've read several threads about relay #44 in the manual it's labeled rear defogger which is it ? And read several other possibilties but all others had some interior and exterior light malfunction and I dont, Just no response using the stalk,
Any sugestions ?????

 

Similar problem with my '99. The auto headlights work, but the switch is hit and miss as far as opening the headlight doors goes.

I haven't sorted it out yet. It sounds like the relay under the hood is clicking, so I suspect the grounds or the headlight door module. If the relay isn't clicking when you turn the switch on, it could be the switch. Had that problem on another GM car, and used a squirt of contact (electrical) cleaner to clean it.

Bill Curlee has a great post on the grounds, and they can be a problem. The one that affects the headlights is on top of the frame on the passenger side, just behind the right headlight and next to the radiator surge tank. Again, if you turn the switch and a helper hears a click from the power dist box on the passenger side near the battery, I'd start with Bill's post and clean that ground. There's another one out at the end of the rub bar under the passenger side of the front bumper. To get to it, you have to remove the close-out panel and the horns. The splice pack for the grounds is taped to the harness way out there. Again, clean it with a brush or contact cleaner, and think about using some tune-up grease (silicone grease) to seal it up.

If none of this works, it may be the module, which is below the passenger side headlight. It could be a bad connection, so clean the connectors going into it. It could also be a bad module. They apparently do fail with some frequency - I've read other discussions of them.

If, on the other hand, there is no clicking when you turn the switch, you need to probe the harness to see if it's a failed relay. If so, you're able to change that pretty readily. If there is no voltage coming out of the BCM (under the passenger floor), you may need to change that. The dealer needs to use a Tech II to program it for your car, but GMPartsDirect.com is a good source at a much lower price. These aren't available as an aftermarket rebuild at this time (or at least weren't a few weeks ago) - GM only.

Good luck.

 

Thats some good advice from BowTieRocket

From what you say I assume the lights are on but the covers stay down.

The first thing I'd tie down is whether its the switch.

If the auto lights (twilight sentinel) on the DIC works OK chances are the switch is the problem. Try some electronics cleaner first. Shoot it into the switch and recycle it firmly to see if it will work. If so theres the problem and theres a DIY fix by swapping it out. If not there are a few other things (headlight motors/modules) to check but as BowTieRocket says, grounds would be a good start.

 

Will start cleaning ground points 2day.......Happy New Year

 

THe headlight doors opening on my 99' are hit and miss. Most of the time they miss. I don't hear a click on the relay until they open. Where is this relay so I can check it out? I also cleaned the grounds and found no corrosion.

 

Where is this relay. My headlights don't open and I only hear a click when they do work. I need to check/replace this relay if I can find it. But how do I identify it?
Thanks!