Measure the resistance across the two sockets on the compressor and the resistance from each pin to the case of the compressor you should be able to detect the magnetic clutch coil. Post the results in your thread. Regards Peter

Smads. Just to advise you that a voltmeter measures potential difference and not presence of current. Checking voltage at the plug with it disconnected merely proves that as in this case there is a difference of 14 volts between the two points. It does NOT prove that current can flow, and so this is not a reliable test. A voltmeter is an excellent diagnostic tool for finding circuit faults, but checks must be done under load. Re-connect the plug and check again, especially if the coil resistance is good as you say it is. You may find that you may not have 14 volts at all with the plug connected, and so you may have a poor connection in the supply cable or a poor earth connection. Use your voltmeter to check each in turn.....