Short circuit detection

One method of finding the short circuit point is to remove the fuse and connect a test light or voltmeter to the fuse terminals when all other electrical equipment on that circuit is turned off. There should be no voltage in the circuit.

Move the wires from side to side and watch the control light.

If it lights up, it means that somewhere in this area one of the wires is shorted, probably in the place where the insulation was worn.

The same test can be carried out on any other element of the circuit, including the switch.