In addition to the compressor seizing up, the overload protection can also trigger without mechanical damage. One cause can be uneven vibrations, for example. Defective components such as the overrunning alternator pulleys, the belt tension damper or the vibration damper on the crankshaft are most frequently responsible for this. Alternating or excessive force can also trigger the fuse. Reasons for this can include uneven engine running, hard gear changes or an increase in torque due to chip tuning.

In rare cases, vibrations knock out the teeth of the pulleys on the drive shaft of the compressor without the overload protection being triggered. The teeth are worn away until the power transmission and refrigerant delivery collapse. An indication of this may be a loosened or missing central screw on the pulley.

A liquid hammer caused by too much refrigerant or compressor oil can also trigger the overload protection. It is therefore worth carrying out a detailed damage analysis before replacing the compressor.