65 Dart Heater AC Fan Problem

sgrip65 said
Hello Members. On my 65 Dart Restoration, I have a problem which I have been unable to resolve. Using my push button controls for AC and Heat/Defrost, my fan functions when I am on AC and Max AC, but not on Heat or Defrost. I have three different fan switches, and I have tried them all with the same results. I have a new push button vacuum switch which I purchased from Classic. All of my vacuum hoses have been routed appropriately and double checked....the wiring as well. So I pose the question....what can be wrong? Does the car need to be running to produce vacuum at the dash vacuum switch? Could it be an actuator? I have no clue, so that is why I am asking. Thanks for the help on this puzzle. Much appreciated. sgrip65

The engine must be running to create vacuum, but I don't think that's your problem.
Note on the wiring diagram below the wiring to the AC & heater vacuum switch. That's where I believe your problem is. Are the wires properly connected and attached properly? The reason I ask is that switch is whaat activates the blower motor when the defrost and heater buttons are pressed. They also control the AC function, but that's working, I'd rule those connections out.

A-C wiring diagram.jpg