headlights won't stay on or work

[blueflame6]

my 1966 pontiac caialina convert. headlights start flashing on and off after they have been on for awhile. i've tried 3 different switches and none of then did the trick. is the prob in the wiring or what else could it be.so far seems to be a prob that cannot be solved. now the lights went out completely but the tailights work.

[Larry]

We have the 1966 Pontiac Service Manual on-line if you wish to check it out.

However, I checked it quickly and cannot find any fuse or relay in the light circuit. A fuse would not explain why they flashed and then later worked again, but a relay would (they can poop out and then reset themselves).

The "flashing" sounds like a loose connection, but it can also be a "poor" connection that heats up, becomes intermittent, and then quits completely.

I have an idea. I had a '67 Ventura that shortly after buying used to leave me sitting completely dead. After a short while it would operate again. It turned out to be the big harness plug that connects at the firewall. They used an electrical grease in them that eventually works more like an insulator after many years. Try unplugging it and clean it out real good. WD-40 is a good electrical contact cleaner. Let it evaporate and then reconnect and see what happens.

The only other hope is to get a small voltmeter and begin tracking from fuse block forward. A jumper from the battery to the lights will give a quck check of bulbs, but I suspect they are fine.

As another thought, I have heard of the same problem being solved with a new dimmer switch. Remember a little wiggling and tapping on items sometimes shows the cuplrit. Them take apart and clean real good.

Let us know what you find.