Compressor / mag motor control issues

I would almost bet it is NOT the contacts.

You can do more damage with trying to clean them "than not" by removing the coating on the contacts

BEFORE you decide to mess with the contacts, try this:

Pull the power to this disconnect, and make yourself two no12 jumper wires about a foot long with ring terminals, and simply bypass the contactor with your jumper wires, left side top to bottom, and right side top to bottom


Then turn the disconnect/ breaker back on and see if you temporarily "cured" the problem.

I'm betting you did not.