*FOUND THE SOLUTION!*

The Problem is: compressor clutch won't engage with a/c turned to max and fan on.

I have searched the existing threads. I've read up on the simple relay hack thread. I've used my voltmeter to test the condenser pressure switch pos and neg. Still stumped on my A/C problem.

So, my friend and I applied power to the compressor clutch using his portable battery. The clutch grabbed happily, and we recharged the system using Freeze 12 (knock on wood!). The air conditioning blows cold inside just after one can of Fr12. Apologize, do not have pressure readings but can obtain them if they are critical to solving the problem.

Here's relevant information regarding the problem:

-R4 Radial Compressor
-Manual Climate Control (Wheel-type AC switch)
-The compressor clutch is Known Good.
-No power at the compressor clutch plug.
-4-pin plug that the A/C wheel plugs into: one contact is hot, tested w voltmeter.
-Using Fr12 instead of R12.
-Cannot hear any leaks in the system.



Common points of failure? Senior member advice? Electrical diagram? Thanks in advance.

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1982 240D 4spd, 327,000mi