Well the high side pressure causing problems is not due to a high pressure sensor. On the back of these compressors is a rotational sensor. The computer matches the rotation of the compressor to the rotation of the engine. If the computer senses that the compressor is turning less than the compressor it assumes that the compressor is locking up and interrupts the clutch circuit to prevent compressor debris from being strewn through the system.

This system has since been determined to be a bad idea and abandoned in later vehicles. The reason that excessive high side pressure can cause trouble is that it makes more resistance to rotation, thus sometimes making the belt or clutch slip, causing the sensor to trip out. A worn compressor that allows thrust movement of the innards can also indicate to the computer a locked compressor and cause shut down.

Monitoring low side pressure offers no data while troubleshooting this problem. You need a high side gauge in order to determine if there is excessive high side pressure.

OCASIONALLY you can correct this problem by spraying down the clutch with brake cleaner and letting it drip dry. If there is any oil in the clutch, cleaning it out can be just enough to let it operate a little longer. There's no point in trying this trick before testing high side pressure.