A/C compressor wont kick on

[petefias]

Originally Posted by VetteMed

Little concerned about the "has plenty of freon" comment, as without evacuating and weighing the refrigerant, that is a conclusion that really can't be made.

Measuring high and low side pressures while the compressor is running, can give some idea of the state of charge, but is not really a way to be sure there's a full charge.

To see if a low charge is what is causing the compressor to fail to kick on, the low pressure cutoff switch terminals can be jumped. this is the switch in the low-pressure (suction) line, as it leaves the evaporator core. Unplug it, jump the terminals on the plug of the harness, and see if the compressor kicks on. If it does, it's either a bad switch or a low charge secondary to a leak.

Spot on. That's exactly what I had to do.