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Discussion Starter #1
Does anyone know of the location of the ac relay on a '81 rabbit pickup? My ac is not getting cold at all. I think it's charged correctly, but I'm not 100% sure. If I could change the ac relay, I could eliminate that possibility.
 

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The 81 doesn't really have a relay, it has a bunch of switches. The switch that controls the cooling is located at the top right of the heater box, and has a capilary tube that runs to the core.

A lot of issues with your a/c has to do with the heater valve not being fully closed or broken.
The heater valve replacement is a iffy thing and makes turning your control switch hard, so a better valve to use is the 1984 Porsche 944 non-vacuum heater valve. Make sure that your valve is fully closed prior to buying a new one.

See Chris's wiring guides.
 

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Discussion Starter #3 (Edited)
Ok. My ac compressor doesn't seem to be engaging, but The clutch turns freely by hand. Also, it doesn't seem to have an expansion valve or at least I can't seem to find it.

I checked the pressure again and the gauge said it was 110 psi!?! I'm not sure how that happened.
 

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The expansion valve is inside the cabin on the left hand side of the heater box.
The compressor is tuned by hand by the nut in the middle of the compressor.

expansion valve.


The a/c cut off switch to cut out the compressor is next to it with the Capillary tube into the evaporator core to prevent freeze up.
 

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Discussion Starter #5
I tried turning the nut in the middle of the compressor by hand, but there's no room there. I was able to turn the whole outer disc by hand and the nut turned with it.

I'm going to try replacing the expansion valve first to see if that helps. I'd rather not replace the compressor except as a last resort.
 

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yes
 

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Discussion Starter #8
Okay. So I got the porsche heater valve, but I'm not sure how to install it. There's an arrow on it which I pointed in the same direction as the old one. However, the cable is now on the bottom. Is that correct?
 

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yes it changes position,but you can rotate it to be on the top...
 

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Discussion Starter #10
I tried charging the ac system today, but the compressor wouldn't engage. I'm not sure if there's any power getting to it.
 

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Down load them they are the wiring diagrams for the Westy, and have good pdf's of the relay locations.
On the westy's there really isn't a relay.
I would start by jumpering the compressor directly to the B+, there is a brown wire that is ground and the other color is the +12.
IF you jumper it and the compressor clicks then you know that the compressor is good, and that you need to trace out the wiring.
The High pressure and low pressure switches are normally closed, so they should be a direct short.
You did use the suction hose or low pressure side port to charge the system? usually located on the strut tower.
There is also the switch that is temprature controlled that is on the right side of the a/c box under the foot or floor vent. I have had that mess up.
 

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Discussion Starter #12
Hopefully, westy's are similar to my pickup. I tried to charge it using the low pressure port next to the compressor.

My compressor only has one wire. Do I jumper that to the positive side of the battery?

How do I test the temperature controlled switch next to ac box? Where can I get a replacement?
 

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to test the a/c temps switch you push on the relay contact.
To test the compressor there should be a connector that has 2 wires in it, one Brown the connector on mine is located here;


Jumper the non-brown wire to the positive battery connection. If it is working it will click.
Same as the a/c sliders have to be in the blue or in the defrost area, heater fan to position 1 or 2 key on then if you push the thermo switch it will click the compressor.
 

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Discussion Starter #14
Well, I tested the compressor by using jumper to the positive battery terminal like you said and I heard a click. So it must be good.

What do you mean by "push the thermo switch"?
 

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On the side of the heater box, passenger side. Up at the top, you may have to remove the vent cover. There is the Thermo-switch it is a relay controlled by a capillary tube that is inside of the heater box. With the system having pressure, Turn the car on not running, and the a/c in the blue and the blower switch in position 3 if you look at this switch it is a relay and you can manually pick it. If when you pick this you hear the click of the compressor then you probably have a bad switch....
 

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Discussion Starter #16
When you say manually pick it, do you mean use a jumper wire? Sorry I'm really confused here...
 

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Use your finger, or remove the connector and short the pins.
 

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Discussion Starter #18 (Edited)
Well, I finally got around to checking the AC thermo switch, and it looks like it went bad. The compressor clicked like you said and the capillary tube was broken. I was able to pull it out. However, I can't find a replacement anywhere. So if anyone has a good one or knows where I can get a replacement even if it's not an exact match, please let me know. The part number is 175 959 281.

Thanks for all your help Brian. Sorry for the confusion.
 

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Not a worry, you may find a generic one that can be used.

NOS AC A/C Thermostat 85-92 VW Jetta Golf GTI MK2 - Genuine - 176 959 281 | eBay but alas out of stock, You might try partsplaceinc.com

If you want one could wire it to a switch on the DASH...and use it as a compressor on/off switch :)
Cabriolets and Golfs of Euroversion had the switch on the heater controls, in the latter years with the change over to the more Cabriolet dash. The early ones had the switch on the side of the heater box. Not saying that you couldn't get a switch out of a Cabriolet and wire it in... you would just have to move the selector arm to Max a/c.

It is to prevent the Evaporator from freezing up, and allows it to turn off to defrost.
 
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