Hi everyone,
I'm replacing my wiring harness in my '79 Bronco with a Painless 12-circuit harness. The problem I'm running into is that the instructions are written for separate gauges, not the printed circuit type like ours. I've traced out all of the wires and what they go to on the printed circuit, but I can't figure out how the gauges gets their power.

Here's what I have:
Blu/Red = Instrument lights
Yel/Blk = Alternator gauge
Red/Org = Alternator gauge
Grn/Wht = Left turn indicator light
Blk = Gauge ground
Org = Fuel sender
Wht/Red = Oil pressure gauge
Red/Yel = Brake warning light
Ppl/Wht = Brake warning light
Pnk = Seatbelt warning light
Grn/Blk = High beam indicator light
Wht/Blu = Right turn indicator light
Red/Wht = Temp gauge
Blk = Light ground

According to the Ford wiring diagram there should also be a Blu/Grn and a Red/Grn wire going to the gauges, but I don't have those. Are the gauges and lights powered by the sending unit wire, or is there separate power coming in somewhere? The Painless harness has wires for the sending units, and a separate power wire that I'm supposed to jumper to each gauge. That doesn't work with the printed circuit. Please don't just send me a copy of the standard Haynes/Chilton wiring diagram, I have those and they aren't helping.

Thanks!

 

I'm sorry I can't be of any help, I'll just take your thread up, maybe someone else knows. You could also try posting your question here: 1973 - 1979 F-100 & Larger F-Series Trucks - Ford Truck Enthusiasts Forums it might get more answers.

 

gauge is part of the circuit. It completes the circuit as the power goes to ground.
For example, the float in the gas tank has a variable resistance, the gauge goes up and down depending on the resistance. The power comes from the sending unit thru the gauge then to ground.