Headlight High-beam wiring

[NYC Bronco]

Headlight wiring question: does the wire from the OEM high beam floor switch go thru the firewall on its own down there or does it come up under the dash and exit with other wires? I think mine has a short and I'm trying to evaluate how much of a PITA this will be before I get under/into the truck. I will probably replace the headlight wire harness when I solve this as well, have a new TBP harness, the diagram for these doesn't cover this for obvious reasons. Thx.

 

[DirtDonk]

As far as I know all the headlight wires run together in the same branch of the harness into the engine compartment. (Edit:and by “all” I mean at least for that side of the truck. Some vehicles run all the headlight wires up one side of the vehicle and then cross over near the radiator. But Broncos should have left and right light harnesses separate.)
What year is your bronco though? That might change exactly where they come through the firewall, but they should still be bundled together.
Even if it's a 66 I think they still carried that same theme.

Do you have a stray wire running through the firewall by itself? If so a previous owner may have had trouble with the highbeams and go on a simpler route.

 

[jamesroney]

Hey Paul,

My 66 bronco with the regulator on the core support has the headlight crossover past the radiator. (along with regulator wiring...)

 

[Broncobowsher]

There is a bonus high beam wire to account for. The one going to the dash indicator light. Make sure that one doesn't have a short as well. And shorts can happen from bad or missing bulbs as well.

But correct, the harness goes through all together.

 

[DirtDonk]

My 66 bronco with the regulator on the core support has the headlight crossover past the radiator. (along with regulator wiring...)

Cool. Thanks for the detail correction!
Love to see pictures of it sometime. Does it cross over from driver to passenger, or from passenger to driver side?

 

[NYC Bronco]

There is a bonus high beam wire to account for. The one going to the dash indicator light. Make sure that one doesn't have a short as well. And shorts can happen from bad or missing bulbs as well.

But correct, the harness goes through all together.

indicator lights up.

 

[DirtDonk]

Is this for the '76 in your Garage pics?

Paul

 

[NYC Bronco]

Is this for the '76 in your Garage pics?

Paul

yes it is, but those pics are from when I bought it and when it had factory lights, I have since gone LED.