Still no power at the low pressure switch 85 300 D

[Diesel Giant]

Ok I am still fighting this horrible problem. On the 85 300 D. I have no power at the low pressure switch. On my searching of the archives, I understand the ACC sends a signal to the Klima, then to the low pressure switch. I am not getting power to the switch. Voltmeter shows no voltage even if I jump the Klima to get power to the compressor.

I hate electricity. I would rather rebuild an automatic tranny.

Can anybody help??

Short of throwing parts at the problem, I dont have many other options left. The Acc seems to do everything right, except turn the compressor on. Or maybe the Klima is bad or both. I wish someone nearby had an 85 that I could swap parts to see if they are bad. My 79 uses a different climate system.