I have an 85 300D with no power to the compressor. The low pressure switch is working (comes on and off with an a/c switch selected.) Can anyone tell me the electrical path into and out of the climate control for the compressor? Is there another switch after the climate control before the compressor? If there is, is there a way to bypass them and would it be safe to do so?

Thanks for any help,
Clay

Try turning the a/c on with the car running and then disconnect the single post wire connector on the water temp sensor located where the top radiator hose goes into the engine. Then look to see if the compressor engages. It worked for me. If this works, you need a new temp sensor.
Tom