[shorod]

Did you have the defroster on when you noticed the compressor was making the noise? If the ambient temperature is above freezing, the compressor will turn on with defrost to remove the humidity from the air.

If you did have the defrost on, it sounds like the A/C system is low on refridgerant. If you want to disable the A/C compressor clutch for the time being to avoid wear and tear on the system, you can unplug the compressor clutch or the pressure switch. Just be sure to tie the unplugged connector up and out of the way of moving or hot parts.

If the compressor is kicking in with the HVAC system turned off, then there is some other issue that will need more investigation. Unplugging either of the connectors mentioned above though SHOULD still disable the compressor clutch.

-Rod