Hi,
My 70’ Supreme has the original forward light harness, fender mounted relay and for the most part, all original dash wiring. It’s an externally regulated alternator and both the alternator and voltage regulator on the firewall were purchased new within last 2 years. On a recent trip around town around dusk, one of headlights went out and I noticed that when the turn signal was on or I pushed the brakes, one or two of the courtesy lights would slightly flicker. It didn’t happen to any of the main dash lights that I noticed. Primarily it was the courtesy light for the vent panel and the dome and sail panels if I had them on. The bulbs are all new and I’m trying to trace down some common things to look for. I didn’t hook up my multimeter yet to see what current the alternator is pushing but that’ll be one spot. When I got home, the headlight was working again but still had flicker of interior lights when pressing brake pedal. With various wires, I wasn’t sure of a good place to start, any suggestions?

Thanks
Tom

 

Unfortunately it could be a loose or dirty connection just about anywhere, but I've been bitten by two things. The first is the wires on the junction post at the horn relay. Remove those and clean them all. This made a big difference on a car that I had with the same flickering problem. The other is dirty or loose terminals in the firewall connector. I've had the terminals back out of the plastic connector body.