[lee]

Been troubleshooting my A/C unit - here's what I've found...

Turn on system and jumper the compressor (at the relay or directly) and system blows cold air - so, no mechanical problems or lack of freon (it's converted to 134)

Turn interior temperature switch up and it lowers RPM and changes over to blow hot air so heat and thermostat portion of climate control works - doors change over properly, etc. Even the outside temp is correctly displayed when pressed.

System will just not turn on the A/C compressor - tried moving up and down the temp dial, etc.

A/C relay is functioning properly by my multimeter tests with voltage applied appropriately.

Hypothesis: I think one of the relay posts should be at ground and one at battery level when A/C is switched on.

Problem, both poles 85 and 86 (standard relay schematic numbering) are at battery level whenever the engine is running.

Question: Does a correctly functioning climate unit send ground to relay position 85 when the A/C is supposed to be on, and hold the line high when the A/C is supposed to be off? Or ?????

tia