Charged my AC system but not getting power to compressor. I have voltage thru the mode switch to the de-icing switch. I jumped the leads at the de-icing switch and there is power to the compressor. It is my understanding that the switch stays open until it detects icing on the probe and then closes. I am wondering if it is possible for the switch to be stuck open? Is it possible to clean the contacts?
Is it possible I have the leads reversed?
I have no idea when the AC last worked.
This is the original AC system on a 69 XR7.
Sounds like the de-icing switch has failed open. Doesn’t matter which lead goes to which terminal since its either open or closed. Never tried to open one up, but a repro is available:
The deicing switch is normally closed and opens when the core drops below a specific temperature. This shuts the compressor off until the temp returns to another specific temperature.
It appears that mine is frozen open.
70 shop manual says the thermostatic icing switch should be open when tested with the sensing tube in a brine solution at 25 deg, then close again “as the tube warms up” with a closed resistance of less than 1 ohm. If the control fails this test, it must be replaced.