The A/C compressor clutch does not disengage when the A/C switch is off
Diagnostic Procedure
Probable cause: The A/C compressor clutch circuit is on (energized) continuously, shorted to ground, stuck A/C compressor clutch relay, or the A/C compressor clutch is mechanically jammed
Do the A/C compressor clutch circuit troubleshooting, and repair any circuit problems
If the A/C compressor clutch circuit is OK, then do the A/C compressor clutch check, and repair any problems with the A/C compressor clutch
Also Check for
Do the A/C signal circuit troubleshooting
The A/C compressor relief valve. If it has vented refrigerant to the atmosphere, correct the problem with the A/C compressor clutch or clutch circuit, then replace the relief valve
Poor or loose connections at the terminals