ac problems 1972 c10

[bdnbfrank]

I recently purchased a 1972 c10. The a/c does not work. When you move the control to a/c the compressor tries to come on but i am getting no blower motor. I have checked the fuses of course and the are good. I tried jumping out the blower switch and no go. The blower motor works if you put power to it with a jumper wire. Where should it start looking first to get it to work. The owner says the a/c was working but the truck had not been driven in a while.

Can you guys help me?

[Davidf]

Check both the anti-dieseling relay (located on lower dash lip between glove box and climate control panel) and the blower motor relay (located on right side of heater core box, behind glove box). Simply disconnect the anti-dieseling relay when testing. If the low/medium speed resistor is faulty (located in air distribution box), the fan should still work on high speed as the resistor is bypassed.

[bdnbfrank]

thanks i will check it.