Wiring Loom Repair VW Camper Van (1974). Incorrect tow-bar wiring and number plate lamp causing short circuiting.
A customer contacted me because he’d noticed melted wires in and around the fuse box of his VW camper van, and when the engine was running the connectors were getting hot. He also said that every time he switched the side lights on the fuse would blow.
Wires melt because either too much power is being drawn through a too smaller wire, or if the wiring loom isn’t mounted and secured properly the loose wires move with the vibration of the engine, and rub against other components to the point they wear through the insulation of the wire, allowing the metal core of the wire to come into direct contact with the metal of a component, such as the steering column.
To carry out this repair, it was not necessary to remove the wiring loom from the vehicle. Before investigating the problem I disconnected the battery to prevent short circuiting of any other wires while I was working on the loom. Firstly, I replaced the wires that were damaged. I could then trace the cause of the faults to two issues. 1. At some point a tow-bar had been fitted on the vehicle, and although it had been removed before the customer acquired the vehicle the wires were still insitu, and it was apparent that it had been wired incorrectly, and as a result it was causing a short circuit in the wiring loom, also known as shorting out. 2. The number plate lamp had been previously wired up the wrong way around.
The photo shows the comglomeration of wires under the dashboard, which all had to be traced back to the fuse they were connected to before I could identify the cause of the problem.