This is where it gets really weird. I was driving along, headlights on, everything was going normally and all of a sudden my headlights went out. The headlight doors remained open and the parking lamps and fog lamps remained on. Then, every six to ten seconds, the entire electrical system would go down for a fraction of a second. This continued until I turned the headlight switch from low beams to parking lamps. Upon doing this, the cycling of the electrical system stopped. Then I turned the switch from parking lamps to off. The headlight doors then shut as they should have. I attempted to turn them back on, and the doors would not flip open again. At that point, I had to return to work. When I came back out of work (where the car sat for quite a while), I turned on the headlamps and everything was functioning normally again.
Since then, what I have discovered is that if the car sits and idles with the headlights on, they will stay on. However, if the car is driven with the headlights on, it will go for about 20 to 30 minutes, then suddenly, while driving, the low beams will go out and the electrical cycling begins again and continues until the headlight switch is turned to either the parking lamp setting or off.
A new wrinkle that developed since the problem started is that the right turn signal functions normally when the car starts cold, but shortly after it gets going, the right turn signal makes the noise as if it is blinking, but the green icon does not show up on the dash and the flasher unit blinks very rapidly. Neither the right parking lamp nor the right tail bulbs flash while this is happening. Additionally, the hazards are not working properly, and I even blew a fuse once when I turned them on.
Thinking that the problem was probably somewhere within the wiring to the right turn signal, I replaced the front turn signal lamp fixture this past weekend, and removed the spare tire cover in the trunk and the right tail lens and jiggled wires and visually inspected wires, and after all that, got the same results.
It seems like it could be one of several problems. It could be an issue with the wiring that I have not yet found, it could be the headlight switch, it could be the flasher units for either the turn signals or the hazards, it could be the daytime running lamp module, or the DRL relay. I have also read where some Firebird owners have had their lights flicker due to a bad alternator.
Short of buying $500 in parts and installing all of them, I am at a loss to think what my next move is. This is making me crazy. I long for the time when I could just reach behind the GTO's dashboard and start testing components and wires, without worrying about an airbag blowing up in my face. In reading on the NHTSA's complaint board, this seems like a fairly common complaint. I think I found close to a dozen complaints over the model years '97-'02.Douglas HerbertVia Internet
Ray T. Bohacz responds:Electrical problems can be very frustrating since they often defy explanation. Not until the car is fixed will you or anyone else be able to state with any confidence that the issues were or were not related. It is my educated opinion that the problem with the directionals is a separate issue and not related to the headlights or the electrical cycling, as you call it.
If I were working on the car, the first thing I would do is unplug the wires to the headlight motors once the problem shows itself. It is possible there is a short circuit in the motor windings that is stealing the current. If that doesn't produce results, keep unplugging components in the lighting circuit to see if you can isolate where the fault is. Try the headlights one at a time, marker lights, rear lights, etc.
Next, check all of the ground circuits using a voltage drop test with the headlights turned on. You need to load the circuit to get an actual assessment of the ground path. The last step would be to check the alternator diode pattern on an oscilliscope to see if it is putting out unrectified AC current. On a modern car, this will drive the electronics completely crazy. Good luck and let me know how you make out.