The wire runs from the freeze switch to the CE panel, in there it splits off to the W24 terminal on the panel(LH) and the M21 terminal, which then goes straight to the low presssure switch then from there through the 14-pin connector and to the compressor clutch. If you're not getting 12V switched via the AC button at one terminal of the low pressure switch, then the wire betweeen there and the CE panel s the problem.

I understand that you don't want to open a can of worms digging into the charred harness, but IMHO that's what you have to do. There could be other problems waiting in there.

 

I see... is which one is the low pressure switch? There are 2 switches on the dryer, one on top and one on the side.

 

Low pressure switch is the one on the side. Hopefully the correct wires are routed there as well. One of them goes straight through the 14-pin switch to the compressor.

 

So if I have power on the low pressure switch I can skip the ce panel check, right?

 

I thought you had a problem with the AC always being on with that switch jumped? That means, once it's full of freon it will always run. What am I missing?

 

I obviously had the wrong wire activating the compressor clutch. Remember you pointed out that the green wire was not supposed to go to the compressor? So now I need to find or fabricate the correct one...

 

Do you have the wiring diagrams? If so I can easily point you to the various grid locations where you can find the details for each wire.

 

As others have said...if the system has no Freon and all is working properly the clutch will not engage. Its running all the time because its jumped....thats bad! Un jump it, replace the dryer and pull a vaccum...If it holds overnight then charge it and see what happens.

 

Ok, let me run this by you all, let me know if I understand everything correctly. With ignition on and ac button on I should:
1. have power on both terminals of the freeze switch
2. have power on one terminal of the low pressure switch
I do have all of the above conditions.
I have no wire going to the compressor. Should I use the black wire of the low pressure switch ( one that does not have power right now) and run it to the compressor? Is that not the way the system was set up to work originally?

 

Yes, you have it right.

The wire to the compressor should be a black wire(Schwartz is German for black, that's why the wire diagram the DR posted says "SW" fo rthat wire). It should go through pin 9 of the 14-pin connector as shown on that diagram.

 

Awesome, thanks so much! I'll charge it up tomorrow and run a wire from the low pressure switch to the compressor. I'll let you know how it works...

 

Started going through the motions and discovered the low pressure switch was not holdind pressure. Ordered a new one. Update to come...

 

An excellent time to replace every O-ring in the system, or at least every O-ring that you can get to. These are the most common leak points, and it would be nice to have new rings that are good for R-12 or R-134a.

Every joint is sealed by an O-ring. If you call Jeanie, she can send you a kit of all of the correctly-sized O-rings of the correct material. (828) 766-9280

 

What are the correct pressures for R134 on a dual ac 1986.5?

 

I don't think its a pressure issue - you need to ensure you fully evacuate the system & fill to the correct volume/weight for your model year & configuration (front only or front+rear).

Pressure will vary when its running & based on temperature etc & without it running you will have uneven distribution.

Alan