I don’t know why electricity hates me right now. I installed a entire new underdash wiring harness and A/C harness in my 71 valiant after the original died due to a electrical short. Everything works except the HVAC controls for some reason. For reference the car is a 71 valiant scamp that was a factory A/C car. The car is all stock and original other than the swap from the A904 to a A833OD and a upgrade to a modern A/C compressor using the bouchillon kit. Everything was working fine before I had to replace the harness.

Current problems:

-No power to the HVAC controls other than the blue and green wires which connect in the center of the vacuum control. (red arrow in pic) These two wires have 12V to them all the time when the ignition is on.

-With the ignition on, there is no power to any other wires attached to the HVAC controls including the fan regardless of the positioning of the switches.

-There is a constant 12V going to the A/C compressor clutch all the time when the ignition is on. I have it disconnected currently so as not to hurt it.

Also, while the electrical controls are not working, the vacuum controls do appear to be working properly.

A couple more pics to follow, but

Thanks,
-Jon

Here you can see how I have it hooked up to the fuse block. Both the green and orange wires have 12V to them.

Here is the bulkhead where the green and blue HVAC wires hook up.

Temp control switch hooked up. Does it matter which wire goes where?

Last pic. Heater motor resistor hooked up.

If you have a 12V Ign source feeding into the heater control can you test the circuit that turns the "heat" or "a/c" on and see if either is working? From what you typed the answer to my question is "no". That said, if you turn on the "heat" or "a/c" does the blower motor function? If no I'd guess that you have something wrong with the heater control or 12V is applied to the incorrect terminal. Can you supply a copy of the wiring diagram? That would be very helpful. Please don't make me get up and walk across the living room.

I have been looking at the diagrams in the FSM and I have 2 observations for you; First there should be 12v to the black wire in the center of the red plug which is fed from the circuit next to where the green wire is attached in the fuse block (black with white tracer). Second, and this is just by the diagram, it looks like the blue and green wires should swap positions at the vacuum switch. I am unable to upload the diagram but hopefully this will help.

They have the diagram in two locations. It is in the Valiant accessory wiring on page 8-165 on the top of the page, and in the A/C section page 24-52. Glad I could help, Mike

Here you go blown340.