Kubota squeaky AC compressor

[Komrade]

Initially thought it was belt and tightened it, but it didn't help.
Sounds like clutch is not catching.
Any pointers to fix and diagnose it myself much appreciated.
Does not squeak with AC off

 

[Harry in Ky]

Check the voltage to the clutch when it's turned on and supposedly operating. If it's less than 12 volts then try "jumping" battery power to the clutch and see if it still slips when running under load. Could be a bad clutch (even a bad compressor or system charge I guess) or could be it's just not getting full voltage.