I cannot get my '95 Jetta's AC compressor to run. I get voltage at the switch and I can't find find any broken wires, but I cannot get voltage at the compressor. Does anyone have a wiring schematic? The Chilton's Manual absolutely blows; it doesn't cover AC at all, or it might just make a mention of it. Is there a fuse or a relay? Is there supposed to be voltage supplied by the radiator coolant sensor? I traced the compressor wires to a box (relay? module?) under the coolant tank. This AC thing is driving me crazy.

 

There is actually an AC cutout switch, on the coolant flange?? Do you know where it is?? Is attached on the right side of the engine block. You can see the coolant hoses meeting there. The one on top is your AC switch.
Let me know if you have anymore questions.

 

I checked the sensor or switch on the top of the coolant flange today. It has two wires going to it- a green and a green/orange. I assume it's a normally closed (NC) switch that opens when the temperature goes too high? The switch was closed when I checked it, so it's not that. What all is involved in the AC system electrically? What components and locations? Does the radiator coolant sensor also act as an AC cut-out?

 

Check you fuse box, because there is one fuse and also a relay. I will give you this website. So you can see for yourself. http://alldatapro.com/alldata/PRO~V1...51182/56251190

 

Thanks for your help. I actually found a wiring schematic online today and it helped immensely. I checked the pressure switch at the dryer and terminals 1 and 2 were not closed; from the schematic, it looks like between those two terminals, they should be normally closed. So, I put in a jumper wire between those two terminals and the compressor came on. Is that pressure switch bad or does the system need a charge of refrigerant? I let the system run for about 5 minutes and I never did get cold air out of the vents.

 

Yeah, just replace that switch and then recharge the A/C. After that you should be all set.

 

Is recharging something I can do myself? I see they sell cans of refrigerant in auto parts stores, but you'd think when you break the lines, you'd get air in the system?

 

yeah, if you have done some before. But, here i found this website with good instructions on how to do it... hope it helps u http://www.ehow.com/how_4454112_rech...-freon-vw.html

 

Thanks for the link! I wonder if the pressure switch is open because the refrigerant pressure might be low? Or maybe those terminals (1-2) are opened by excessively high pressure and should be closed now?

 

They should be closed... Did you already try to recharge it?