Paul- this 1967 Bronco is new to me. Iv had it about 6 months. There was a heater box with motor in the truck but there were no Heater/Fan, Defrost, or heater knobs in the truck. and no power running to the heater motor. But the Red and Orange wire component was there and one end was free and the other end was attached to the resistor on the heater box.
I looked all around the Fuse box which I posted up top and there was no Brown wire coming off the 20 Amp fuse. I spent hours under the dash searching for a brown wire to no avail. The electrical harness is also missing the wire that goes to the Cigar lighter. I suppose the Brown wire was ripped out at some point. The electrical wires all look original except for the wires someone added for power to a crappy stereo.
Yesterday I drained the radiator, removed all the heater hoses and replaced them and the heater valve in the heater hose. I removed the Heater box, took it all apart. Cleaned and sanded the heater box, cut a larger hole for the HD Heater motor and larger squirrel cage, painted the heater box, replaced the heater core, resistor, all the seals, and the inlet hose for the air. I installed new Defrost, Heater/Fan, Heater switches and attached the cables. Now I just need power the Heater/Fan switch. I also installed new defrost hoses and the Defrost ducts for the windshield.
Ill try To attach a 14 Gauge wire to the ignition post and install a 30 amp inline fuse and attach it to the Heater/Fan switch.