A/C Heater wiring question

[bil1024]

I'm running Ford 302 in this Gen 3, with speedway wire harness, 1 wire from harness for power. I can follow some of the instructions but its like a am missing a part of the harness ? Grey wire from compressor to red wire on drier and 4 wires from controller to a/c unit, yellow / green/red /black and that's where I am stuck

[bil1024]

ttt

[David Williamson]

sorry you are not being ignored but you are using a different wiring harness, most of us have the Painless one from FFR. So I can't give you any help on this one.
David W

[Alphamacaroon]

As David mentioned above, I think most of us are using the Ron Francis harness, so it's a little hard to give you an answer. But here's some additional thoughts to help point you in the right direction.

As far as I know, you really only need to connect the AC/Heater unit to two places in the chassis wiring harness:

1. You'll need a fused (20 amp recommended) +12V power source. Preferably something that is connected to the accessory (ACC) switched portion of the wiring harness. This gets connected to the B/BRN-HEATER +12V terminal on the FAN switch (along with the RED-BATTERY FEED that goes to the valve controller box as shown in the wiring diagram).
2. You'll need to connect the RED-BLUE wire from the TRINARY SWITCH (labeled as LT BLUE - GROUND in the diagram) to the relay that powers your cooling fan. I believe you would need to connect this to the low power side of your fan relay, terminal 85 or 86 (can't 100% be sure on the terminal number, but others might chime in). But effectively what this does is allows the AC system to turn on your cooling fan (independent of a thermostat switch, ECU, or manual switch) to cool the condenser when it senses pressure in the system.

As far as I know, all of the additional wiring is self contained to the AC/Heater system and should be exactly the same and done according to the AC installation manual.