Compressors have internal moving parts, to compress the gas to a liquid. I've heard of a high pitched noise happening a few seconds after it turns off. That usually means the valves are scarred and freon is leaking back through the pistons/valves. Are you sure it's the compressor? Maybe not the fan? Otherwise it might be bearings going bad. how old is it? Warranty? if so, return immediately or call for work.
2015 Georgetown Forest River 351DS MH
2008 Keystone Cougar 293SAB 5th Wheel
2007 Jay Flight 30.5RLS 5th Wheel
2006 Jay Flight 29BHS TT