This article contains the detection of defects in your Ford F-550 Super Duty A/C compressor and condensing units, including evaluation of air conditioner compressor noises, hard starting, lost cooling capacity, and the detection of a burned out compressor at or near the end of its life, among others.
If someone turns the thermostat air conditioner up and down or on and off too frequently, a hard-starting compressor may find that it was shut down with high internal head pressure inside the air conditioning compressor. But if someone is turning the system on and off quickly, the compressor may find it has a hard time restarting against the pressure on its outlet side. A starter capacitor addition or replacement could probably fix this no-start condition. However, a service call from a professional to correctly diagnose and repair the problem is best.
A/C humming, clanking, or buzzing noises can indicate either a minor or a serious problem. Is the noise somewhere else and perhaps from another source that has nothing to do with the air conditioning system? Banging or clanking air conditioner noises are usually due to a loose connecting rod, piston pin, crankshaft, or other internal parts. Since compressors on most modern air conditioning systems are a sealed unit, the only repair for this condition is to replace the compressor.
A catastrophic refrigerant leak on the air conditioner will make a loud hissing sound. You would probably hear bubbling sounds at the refrigerant piping or see bubbles in the sight glass if your system has one. Refrigerant leaks prevent the production of cool air in the air conditioning system and admit moisture and dirt contamination into the same. You may be able to repair the short cycling problem temporarily by recharging the A/C system, but it is recommended that you find and fix the leak. Otherwise you'll just have to keep calling a professional to add refrigerant.
An air conditioning system's inability to cool could be due to a loose or worn compressor, which has lost its ability to "compress" the refrigerant. This condition can be diagnosed by an air conditioning service technician who will install air conditioning manifold gauges onto the air conditioning system to check the compressor suction vacuum and discharge or "high side" output pressure.
Unlike a high-amp current draw which indicates that the compressor is damaged internally in a way that its piston(s) is (are) tight in the cylinder, a low-amperage current draw may confirm internal wear on the compressor parts.