Mark IV headlights

[sittonb]

Finished my car a year or so ago. Headlights worked, but never drive at night so....
I tried a night cruise but noticed that the headlights come on, then after a few seconds (about 20-30) they begin to flicker, and go out, back on, go out etc, they flickering is not in sync with engine speed, and they flicker together, not one more than another. Play with wiring behind lights, no effect. If I turn switch to parking lights, they stay steady, just headlights flicker. Taillights also stay steady. This only occurs when car is running. If I turn lights on while engine is off, they stay on.

Thinking it might be the switch, or the switch grounding out when car is running due to just normal vibration but it's going to be a pain to get to the switch, which btw is the FF5 provided switch. So wanting to confirm the switch is most likely or have someone weigh in on another test etc.

Thanks all!!

[Jeff Kleiner]

The switch has an internal self resetting circuit breaker which is most likely the culprit however if you have a weak ground causing high resistance it is doing exactly what it’s supposed to do. If you can verify that this isn’t the problem and that you have good solid grounds on the headlights replace the switch.

Jeff

[sittonb]

Thanks Jeff, I seem to have violated the KISS principle, went to the switch when it was a simple ground issue.