Head Lights Stopped Working

[Sherony]

I have had my 1969 SeriesIIA for a few months now and the head lights just stopped working. I did not fiddle with any of the switches or wiring. When I first brought it home, the drivers side headlight was about half as bright as the passengers side. I figured this was a bad ground I would have to track down. A week later, the drivers side headlight perked up and both were working flawlessly. A week ago, they both went out at the same time. The driving lights, turn signals, brake lights, etc., all work fine still. The only lights that don't work are the headlights. The brights do not work either. Before I dive too deep into this, I wanted to know if there is a common cause for this kind of behavior on this truck. Is it a busted ground? Any guess where? Is there a fuse that could have blown? Electric systems are not my forte'.

Thanks in advance.

[SafeAirOne]

One of the usual culprits is the dimmer switch. It's easy to check though; With the headlight switch on--just remove the blue wire with the white tracer from the dimmer switch and touch it to the blue wire on the dimmer and see if the main (high) beam comes on. Do the same with the blue with red tracer for the dipped (low) beams.

If they both work this way, but not connected to the dimmer switch, then the dimmer switch is bad, of course.

[bobzinak]

Sounds like a bad ground wire..On my 2A the ground wire is in the center just in front of the radiator behind the grill screen, the high and low beam wires get split up with the bullet plug connector make sure those are clean. take a close look at any that are near the battery, those are famous for having problems. get a 12v. test light probe,cheap item, and trace down the voltage loss. you could start at the dip switch and work forward to the head lights. sounds as if you need to clean up the connections in the headlight wiring. don't forget to spray some contact cleaner in your headlight switch. I've had switches get dirty and make the lights fail..but not just one headlight..which makes me think that you have a bad ground wire..bobzinak

[Jim-ME]

I have to agree that it is a bad ground. Check the one at the radiator support. If I were you I'd replace the bullet terminal with a ring terminal unless that has already been done. When I lost my dimmer switch I had low beams but no high beams. Clean all the connections and you should be good to go.
Jim

[Sherony]

I started with the dimmer switch and it looked like the wires had been repaired by a 6 year old. I removed the electrical tape, and found that they had corroded through in many places. I cut the wires back until corrosion was almost non existent, spliced in new wire, and soldered the new wire to the harness. Headlights are working. I enjoyed staying out last night and not having to race the sunset to get home.

Now the original problem persists, and that is a dim drivers side headlight. I will check the grounding locations you guys recommended later this evening. Thanks for the help so far.

[mongoswede]

I always look at these situations as a good opportunity for an upgrade. You could lay in some good quality wire, a modern relay, and modern fuses and rewire the headlights. Impact is brighter headlights on a safer circuit independat of the stock electrical system (except tied into the key and charging system). There are even some decent ready made headlight harness that can be dropped in. But the stock system can work too