Dealer installed AC not working

[funnyman06]

So my 85 has the dealer installed AC with the york compressor and all that jazz. After sitting all winter I went to kick it on and nothing happened. I cant get the blower fan to work nor does the AC clutch try and engage. I was wondering if anyone had a wiring diagram or has torn through one of these before and could give me some direction where to start looking. I found a fuse under the glove box that I believe is for the fan but it is not blown, so without tearing the whole dash apart i'm at a loss for the moment.

Thanks,
Chris

 

[icanfixall]

The fan works no mattr if the ac works. Thats a safety item. If all fails you at least have air blowing on the windshield. You may have a freon leak. When the pressure drops the switch on the side of the ac dryer will not close for the ac pump to operate. What you can do is remove the wire plug and jumper the two spade connecters in it. But know this. There must be some freon in the system or the ac compresser can be damaged if its run long. Any auto parts store has a cheap freon gauge thats nothing more than colors on the dail. It will tell you if there is enough of a charge to operate correctly. This is the same for both R12 and 134 freon. They both must have a minimum charge to operate.

 

[funnyman06]

Unfortunatly on the dealer installed AC system I actually have two seperate fans. I have the heater fan which works great, blows up for defrost and down for heat. But I also have the whole AC system which includes a small blower in the cab. That fan is suppose to kick on when I switch to AC and increases speed with the 3 fan settings. This used to work correctly, however now when I go to AC nothing happens. I guess ill have to open up the AC control thing and check the brass contacts. Wonder if it got corroded over the winter and is just no longer making contact.

Tomorrow if it helps i can shoot some pics and post them up.

 

[franklin2]

You can either test for voltage out at the fan with everything on, or take the wires off the fan and run two temp wires over to the battery and see if it will run. That will eliminate the problem being the fan motor. I am not sure how they wired up the dealer A/C system. I know on the factory systems they run power to the fan motor, and the speed switch selects where the ground to the motor goes. High is a direct ground to the motor, the other speeds come from directing the ground through different resistors mounted in the ductwork.

 

[funnyman06]

Franklin good to know. That will help me understand what im looking at when I start opening it all up.

 

[chris142]

Check for pressure. They dont like to sit unused and often leak from siting