Hi,

I have an 82 PU. My headlights don't seem to want to work. yesterday I quickly verified that the light switch was working, that the relays were working, and that everything was hooked up properly.

If I use an alligator clip to put +12V to the "Always hot" pin of the headlight relay, the headlights will function.

This wire seems to be a heavy gauge wire, Red W/ Blue stripe.

Well, I see a similar gauged wire extending from the harness and connecting to the + terminal of the battery. It looks *exactly* liek the wire going into the relay.

Except... That when I put +12 into it, the headlights still do not work.

Where is the main supply voltage for the headlights coming in from? The fuse box? Perhaps I will check that next, although the fuses are downstream from the voltage, not upstream.

 

I should ask, where is the fusible link? I don't see it anywhere!
Got it, there was a break in the wire in the insulation.

 

Go here and download a FSM for an 83. might help you out.

https://www.yotatech.com/forums/f114...wnload-261385/

 

By the way, the wire used on the headlights is called "fusible link wiring". Basically, it is built in such a way that if it takes a dead short, a section of wire will blow out. The stuff is actually kind of a PITA, it can make troubleshooting a problem quite difficult.

Voltage to the headlights will come from a 12v relay under the drivers side dash. A lot of times, these relays get stuck or fail. Locate it, and try flicking it with your fingernail or tapping it with something, then try actuating it. You have a50% chance of fixing the problem. If not, you are down to troubleshooting voltage and continuity with a multimeter. Good luck!

 

That red/blue wire does indeed go directly the battery. The fuseable link is near where it terminates on the battery.