How to tell if the A/C compressor is bad.

Hello, the air conditioning compressor may not turn on for a few different reasons. Sure, it could have failed, but also -- the electrical components that sense system pressures and direct the coil to engage the compressor clutch may not be working properly. Or the clutch / coil may not be working properly. Or, the system may be low on refrigerant, which will prevent the system from turning on. Hands on testing by a skilled and experienced technician who is section 609 EPA certified to legally handle refrigerants is strongly encouraged.