I need help with heater/AC for 63 GP

[trobbins]

I have a 63 GP. My air conditioner comes on when I turn the switch but the heater will not come on (I do not have the AC charged). The blower is on high even when I turn it to low. I replaced the control unit with one from a parts car and it does the same thing. I also replaced the two resisters located on the fire wall. Can anyone help me?
Terry

[Larry]

Whenyou say the A/C comes on, I assume you mean the clutch engages.

When you say the heater does not come on, are you meaning that hot air does not blow out of the vents? If so, are you certain hot water is getting into the heater core in the first place. You should be able to feel both heater hoses at the firewall connections to get a good idea if hot water is both going in, and coming back out.

If one hose is hot, and the other cold, you aren't getting water flow, most likely because the valve on the intake or somewhere along the inlet hose isn't opening up.

If you are getting hot water in and out of the core, but no hot air, then it is a flapper valve not opening up, probably because of a vacuum valve under the dash not opening.

Now the blower motor speeds... that's another animal altogether. You replaced two(?) resisters? I'monly familiar withthe one setup that hangs inside the plemun and hase something like three resister loops of wire to control the motor speeds.

The fact that the motor/blower runs is a good thing, but stuck on one speed is another. I'll have to ponder that some more. Other than wired incorretly or a broken piece of something short circuiting another (I've seen that), I'm stumped.

Feed us as much info as you can.

[trobbins]

The blower motor will not work at all when I push the heater button. It does work when I push the deice button but it blows on high even when I turn it to low. I had it charged up today and it blows cold air on deice but when I push the heater button it goes off.

I don't have the car at home right now so I can't check the heater hoses.

[Larry]

It sounds like up is down and down is up!

It sounds like a total mix up of wiring here. I ask, did it ever work correctly for you before? Is the control correct for that car (the one in it before and the one you replaced it with?

I wouldn't worry about checking the heater hoses for now. The core is probably getting hot water, but the wiring of what happens when you hit switches is totally wonkey right now.