My headlights have a bad habit of going dark randomly. When I pull out the headlight switch, the lights will pop up - sometimes taking a second or two. The lights may or may not turn on. If the lights turn on, after a few seconds or minutes they will go out. Turning on the high beams will sometimes get the lights back on. Sometimes they come back on themselves after a few minutes or seconds. Repeat.

Any ideas? If your answer is a bad ground, please tell me where I can find the grounds related to the headlights!

Just a suggestion, try wiggle each wire connected to the headlight motor, I accidentally found a broken wire on my car this way. I noticed the headlight intermittently doesn’t come up but all the wires and connections seem intact. This is until I touch one of the wire and it come completely detached, broken clean at the terminal.

John

If both headlights are going out, I doubt it's a ground. Pretty sure the 2 use different grounding locations, but it's been a while since playing with lights on mine. If both go out, I'd suspect either the contacts inside the light switch, or the wire going from the switch to the fuse panel. These are common points that would impact both lights. If you have a voltmeter, I'd try to check voltage at the light fuses when the condition occurs. Find a good body ground point for the meter's ground wire and then check voltage on both light's fuses. After determining the state at the fuses, then you'll know whether the problem is within the dash or wiring forward to the lights.

Dan

Bad relay?

If both lights do not respond, I guess the problem is in the switch. That is the only common part of the system. Each light has its own power supply from the fuse panel, and its own relay. I suppose you could have an amazing coincidence, like both relays failing on the same day, but I bet not.

I did replace the headlight switch (several years ago) with one that had a better rheostat. I may have the old one still. I'll give that a try and let you guys know.

I found my old switch, but I guess I forgot what a production it was to get behind the dash. It may be a while before I have time to swap out the switch.

So I finally had an afternoon to take apart the dash and I swapped in the other "old" headlight switch I had. It was worse than the "new" one - the headlights would pop up but would not light. The "new" switch would at least turn on the lights sporadically.

I decided to take apart the "old" switch to see if there was anything obviously wrong with it. Aside from being caked with old grease it seems fine. Some of the contacts were black with dirt and grease, maybe that's preventing the contacts from touching? I cleaned it up with contact cleaner and fresh dielectric grease and reassembled it. I'll try to install it in the next few days...

Well the cleaned up "old" switch still does not work (lights don't pop up or turn on).

I took it apart again and had a close look at the contacts. Some of the nubs have been worn down flat and probably are not making any contact. To really fix it I need more donor parts, so I'm going to think about dissassembling my "new" switch and see if I have enough good parts for one working switch.

I know I can probably buy another used switch that works but it'd just be a matter of time before it fails too. I think I'm going to perform the fog light hack while I'm behind the dash so that I can at least have some lights working if my headlights ever go out on me again. It's not fun driving at night and having all your lights go out at the same time. It's actually kind of terrifying on a dark road where I was when it happened to me!

hi lo relay is bad

I took apart my other switch and put the good parts into the first one. Re-installed and now the headlights work perfectly. I also did the "fog light hack" so that my fog lights will work even when my headlights are off. This will give me some extra protection if the headlights ever go out again while I'm driving in the dark.

If I have any other issues I will look into the hi/lo relay.

I would love some advice on a similar problem to this on my 74 1.8. My headlights simply failed to go up and turn on one day last week. After some troubleshooting and struggle, they magically just came on and I was able to get home. I truly don't think I did anything but get lucky. Once during the drive they went out for a second or two. Now they do not work at all, won't come up and no lights on. All the other lights (parking/marker/etc.) do work when the switch is pulled. I have swapped to a backup headlight switch and have the same result, as well as rebuilt the original switch with no change in behavior. I have followed the testing sequence described on the Pelican site (https://www.pelicanparts.com/techarticles/914_headlamp_motor/914_headlamp_motor.htm) and have had no luck.

After much troubleshooting and testing on the switch and studying the wiring diagram, I have narrowed down what I think might be the issue and this is where I'd like some opinions. On the headlight switch, power (12v) comes in on pin 30 via fuse S10 and then when the switch is turned off, runs to pin 30B which actuates the retract function. Power also comes in on pin 15, straight from the ignition switch, unfused, as far as I can tell from the diagram. I have NO power on pin 15. I DO have power on pin 30, and if I take the lead from pin 30 and touch pin 56k (headlight extend function, normally powered via pin 15), the headlights go up and light up. They stay lit up until I remove the lead from pin 30 touching 56k, then the lights go off but the lights stay up in the extended position. I can replace the lead to pin 30, and then turn the switch off and the lights retract as normal.

Basically, there is separate power for extend (pin 15) and for retract (pin 30). I have no power at pin 15 which is straight off the ignition switch. So my long-winded question is, does it seem likely that the ignition switch could be at fault here? I have never had a ignition switch fail in this way, and i've been through 3 or more. This is all I can think of and the diagram seems to follow as pin 15 is fed straight off the ignition switch on lead X. Is my logic solid? Thanks for any input.

For those following along, I replaced the ignition switch today and the issue was cured. As I expected, the ignition switch was not passing power between the input to the ignition from the battery on blade 30 to the output on blade X, which then runs to pin 15 of the headlight switch and then down pin 56k to the headlight extend function.

The photo shows continuity of the new switch between blade 30 and X, with the key in the on position. Again, this is for a 1974 1.8.

Ignition switches fail in mysterious ways.Click to view attachment