I have an 2003 Impala and the headlights stopped turning on. The high beams would only work if you held in the dimmer switch on the steering column. I had the dimmer switch replaced, and that fixed the problem for a few weeks before the same thing happened. Took the car to a different shop and they found a shorted wire near the fire wall, fixed it, and the same thing happened. Headlights worked for a little while then stopped again. Brought it back to the second shop and they replaced the BCM (only charged the price of the part, no labor cost because the problem wasn't fixed), and the low beams won't come on. The high beams will come on, and stay on. This is getting just a little bit annoyinng. Does anyone have any ideas what might be going on with the lights? There are no other electrical issues with the car. Any help would be appreciated.
Thanks.

 

Pull the DRL relay in the underhood fuse block and see if the high beams will turn off. If they do, the BCM is commanding them on. They replaced the BCM with new AND programmed it to your VIN? If so, they screwed it up somewhere. If not, they screwed up as well. Since the odometer is stored in the I/P cluster on yours, it'd be so tempting to throw in a used BCM. The problem is that there's no way to tell a good one from bad AND match your vehicle and options.

 

The high beams are functioning properly, it's the low beams that don't come on occasionally. They won't turn on automatically, and they don't turn on with the switch on the dash. Why will they function the way they are supposed to for a few weeks after some work being done on the car, and then all of a sudden stop working all together?

 

Okay, I guess I misunderstood the current state of the problem, then. Say, you set the dimmer switch to the high beam. Your high beams turn on automatically at night AND they turn on anytime by the headlamp switch? Now, you set the dimmer switch to low beam. Your low beams DO NOT turn on automatically NOR by the headlamp switch? Or, they SOMETIMES do and SOMETIMES don't?

 

Yes. With the headlamp switch pulled out (on) or with it pushed in I can pull the dimmer sw on the steering column to high beam, and the high beams will come on, and stay on. But the low beams will not come on with the headlamp sw in either position. If I use the dimmer sw on the steering column and change from high beam to low beam, the low beams don't come on. Basically, no low beams, only high beams will come on.

 

It may be an intermittent break inside a wire or where it goes into the cavity at the connector. The problem disappears for a while after the wire is disturbed. The wiring path from the dimmer switch to the headlamp relay is the same for both the high beams and low beams and thus it's probably not the culprit. I've seen two headlamp bulbs go out within a couple of days of each other so they can't be ruled out. Also suspect are the wiring between the bulbs and the dimmer switch (actually a single wire that branches to two for each bulb) and switch itself. Have you tried changing the tilt of the steering wheel?

 

Could be a hazard button going bad