OK, you have found and confirmed the failure, good work. There can be more than one thing wrong but step one is finding the wiring fault on that white wire between the HL SW and the UHFB. Again, you may find more than one wiring fault in the area where the white wire has failed.


George

 

Thank you George!!! You are a brilliant man. OK now to temporarily give me headlights what's the next step to do?

Is there a wiring diagram you may have to guide me along? Or is it follow the bundle of wires and see where it gets me.

 

I finally got to use my engineering degree (after 40 years)! LOL. Like all good engineers I live to solve hard problems.

A wiring diagram wont help here because it does not show how the wires are routed. You just have to follow the harness branches from point A to point B. It can be tough especially since you are going into the dash and then through the firewall. A temporary fix would be to tap a wire into both ends, first near the back of the HL SW and then either under the UHFB or at the wire bundle coming out but again, try to find the actual failure. You may have to do some continuity testing to confirm the correct white wire coming out of the UHFB. Do you know how to solder? If not there are some splices that have a knife edge in a crimp assembly to tap into the wires but I have never used those. Always solder permanent repairs or crimp and solder. Likely places are under windshield leaks in the dash or in the engine compartment but of course rodents can get anywhere.

George

 

Your expertise from 40 years ago definitely helped in this situation🙂 And I truly am glad you didn't give up and throw in the towel because of my lack of knowledge on this.
Looks like I have some wiring to follow over the next couple of days. I can solder.
Is it possible to run a toggle switch to the headlights from the battery temporarily?

 

Powering the headlights directly from the battery is a challenge because of the current involved, I mean it can be done but everything would have to be really beefy because we are talking approaching 20 amps in the circuit. That's why the original design uses a relay. The 2 more manageable options are to tap into the white wire with a fused toggle switch and battery power near the UHFB or use a toggle switch and a relay from battery power.


George

 

Another possibility is to solder the fused/toggle switch power wire directly to the relay pin that goes into the 4 o'clock position if you can solder it close to the relay body and then push the relay in as far as it will go.


George

 

Oh ok. I think I'll just use my fog lamps if needed, even though the cops hate it and I had been warned🤣just if I do need to go out at night.

I will update you to what I find. And again thank you for giving me a small amount of your knowledge and helping me. Kudos to you George!!!

 

Your welcome, glad we found the problem and I like your perseverance. Most people give up near the beginning.


George

 

That last idea would look like this:




George

 

Ok. Maybe I can try it that way. Thanks