Checking lamp switches and electric motors (VW Transporter T4)

1. Remove the switch.

2. A simple switch has two cable connections. In this case, positive voltage (+) is always applied to one connection and after switching on, the other terminal is also. There are switches with several terminals. In this case, use the electrical circuit diagrams to find out which terminal should be supplied with voltage.

3. Check with a test lamp whether there is voltage at the switch. If the lamp is on, turn on the switch and check at the output terminal whether there is voltage there. If there is, the switch is working properly.

4. If there is no voltage at the output terminal, there is a break in the supply circuit. Check the direction of current flow in the electrical circuit, if necessary, lay a new wire.