Just bought machine, 2100hrs well kept. When purchased the AC compressor was locked up. Installed new compressor, dryer with hp switch, and expansion valve. Vacuumed system down, put the right amount of oil in, the right amount of freon. Compressor is cycling. Seems to be electrical. Reason for this assumption is i unpluged compressor plugged it back and it worked perfectly for 10mins. Shut machine off to button up a few things and when restarted it went back to cycling again. Any help is appreciated.
Look at your pressures. My first notion is you are going too high, or too low. Or the relative switches have died. Was there oil shipped in the compressor? Was there a tag to say?
Does your ac compressor work with a clutch, and did you install a new clutch (or transfer the old one to the new compressor)? Ac clutches sometimes have wear shims under the friction disk, to limit the amount of disk pressure when the clutch is engaged. If the clutch disk is worn, the shims will cause the friction disk to slip, and the clutch will not drive the compressor reliably. The shims are adjusted by removing them (typically one at a time) as the friction disk becomes thinner with use. If your clutch is new, chances are that the wear shims are not your problem. You can check by removing the clutch and taking out one of the shims (if there are shims under the clutch), then reinstall the clutch and see if the problem is fixed.
How much oil did you add to the system? New A/C pumps usually come with oil in them. If there is too much oil in the system it will cause rapid cycling of the pump and little or no cooling.
The compressor came came dry with new clutch. I added oil(not to much) to both the compressor and dryer. The reason i think its electrical is because ive gotten it to work for 10 mins and it blew cold. Worked as designed, pressures were perfect, and no cycling. Shut machine off restarted a while later and back to cycling.
Check all the connectors, make sure there are none that have expanded and are not making a good connection. Give all the wires at the plugs the "Ten Pound Pull Test" I would assume there is a relay and a fuse somewhere that supplies power to the pump make sure connectivity is good there as well.
Ok guys, thx for all the advice. Turns out it was a combination of the dryer, and the thermostat in the evaporator core. Replaced those and now she's cooling like a champ.