No Headlights!!
 

Ok, as you can tell from the title, I need some help.

Came out from work tonight and started the 83 300D, turned the headlight switch, and no headlights!! Pulled back the column stalk switch and no high beams either!

Here is what I know. All 4 fuses for the headlights look good (what are the odds of all 4 going bad at the same time anyway), the tailights and brake lights work normally, the parking lights, turn signals and hazard flashers work ok, the fog lights work fine, the instrument cluster lights are fine, and the high beam indicator comes on and the fog lights go off when you try to turn on the highbeams, just no headlights whatsoever.

Any ideas? What I am going to try is to check the wiring as I suspect a broken wire or a bad light switch.

If anyone could post a copy of the headlight wiring schematic (with either pin numbers or wire colors) and instructions on how to remove (and test) the headlight switch I would be supremely grateful!

On a good note, as I was driving home (via the fog lights) the car turned over 320,000 miles!

Thanks in advance,

Glenn

I believe there is a headlight ground next to the headlight assembly on, I believe, the passenger side. Might be worth checking.

Bad headlight switch?

Ok, I found a wiring diagram online, and based on what still works, it is safe to assume all the fuses, and the column switch are good, and pretty sure the headlight switch is ok too.
So, I'm thinking a bad ground wire as that appears to be the one common point between the lights......Unless both bulbs (all 4 filaments) went at the same time.

Pull the connector out of one of the bulbs. There are three terminals...one iis ground, one is power for low beams, one power for high beams. Test with a DVM, and narrow down the possibilities.

Good Idea!

That happened to me and it turned out that the headlight switch itself had gotten just loose enough that I was not turning the toggle, I was turning the entire switch. Tightened it up and the toggle turned the lights on and off again.

Ok, I fixed it! Ran some voltage checks and found out that the culprit was the 30 Amp safety fuse I installed between the battery and the two relays I am using to control my slightly (70W/90W) more powerful H4 headlights. Looks like it got some moisture in it from all the rain we have had lately, and simply gave up the ghost. Either that, or it just decided it was time to go, as it had been working perfectly for the last 5 years.

Anyway, a new fuse and holder, and we are back up and running.

Glenn

Always nice when it's an easy fix. Might be worth carrying a spare in your glove box.