Headlight Question [Archive] - GrandAmGT.com Forum


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04-18-2007, 12:25 PM
OK, here goes...

I have a 2001 GA SE w/ 103k on it. I've had the car since it was brand new, and have faced & fixed (myself) almost EVERY common problem/issue concerning this model of car. Therefore, I would consider myself fairly knowledgeable when it come to 1999 + GA's; however, I am completely stumped on this.

A couple of weeks ago, my SVS light came on, so I went through the normal routine of finding the cause. As it turns out, my driver's side headlamp was burnt out. I replaced both sides (just to keep them even), but the SVS light still came on, AND I still didn't have my driver's side low-beam. I noticed, by accident, that when I put it into gear, the DRL's would flicker, then go out. When they went out, the SVS light would come on. My next step was to replace the DRL relay (#22 under the hood). This still did not fix the problem. At night, the automatic lights come on like they're supposed to, and the SVS light does NOT come on. I have BOTH high-beams, but only one low-beam. I have checked all of the fuses and relays that have to do with any type of lamps, and they're all fine. I've even checked conductivity from the bulb to the fuse box. It's all fine. I'm just not getting power through the driver's side low-beam circuit from the fuse box.

I guess the point of all this is, CAN ANYONE OFFER ANY SUGGESTIONS??? Is there a DRL module that could be bad? Could this be attributed to the BCM going bad? All grounds, connections, fuses and wires seem to be fine. I have never had to take my car to a dealer, but I may be out of options. Please, anyone, let me know if you can help me out!

04-18-2007, 01:03 PM
Have you tried swapping the bulb? Sounds like a bad bulb... it happens

04-19-2007, 08:22 AM
Ha! I wish! No, I tried that. The bulb lights just fine when plugged into the other socket.

04-19-2007, 09:34 AM
sounds like a gremlin is in your ride.....Seriously though, it could be one of those elusive (sp?) bad grounds. They can be hell to track down.

04-19-2007, 10:20 AM
Bad ground could be the culprit as Cory suggest.

I would also visually check all the wiring to that light to ensure you do not have a partially broken/corroded wire, which it what it sounds like to me. I had a similar problem w/my Cavy (drivers side) and it turned out the + wire was corroded about 14" into the harness which was original from the factory !! (car was 3 months old). Turns out the harness was wrapped the opposite direction of the pass. side & this allowed water in.

04-19-2007, 11:05 AM
I'm just thinking here, so I could be wrong, but I'm pretty sure there is a single wire coming from the headlight switch and the relay to control the low beams, it is split after the relay to each light, so if one works and not the other, the switch and relay should be fine (you already knew this about the relay though), so logically, the only thing left that I could think of is wiring, pull the headlight out and check everything back there. Like was said before, corrosion can be a bad thing, as could grounds. If it is the wires near the harness, it's a pretty easy fix though, just get another harness pigtail from a parts store and solder a new one on.

04-19-2007, 09:30 PM
The headlights are controlled by the BCM. It provides the DRL's, the auto-on's, the SVS light, etc. There is no simple relay.

Hook a meter to the socket and see what volts are there on high and low beam wires. IIRC the center is always hot and the unlit light wire is also at 12VDC. When the light turns "On", the voltage on that wire drops to zero. The DRL has 12 volts at the center and about six volts on the high beam wire. That gives it the dim look.

04-19-2007, 09:57 PM
I've posted the headlight schematics here before too.. feel free to hit the green button

04-20-2007, 07:10 AM
Well, I tore out the harness and you were right "stangdude". It was a bad wire. I have no idea how it happened, but there was a small kink about 2/3 of the way back to the fuse box. I spliced in a new wire on either side of it, and everything works fine. 'Totally thought I checked the conductivity through that thing once before, but I guess I didn't. Thank you everyone for all of your help, I'll definitely be coming to these boards FIRST for anything I need!