Turned the electrics on today and was a bit scared to smell burning plastic. The battery voltage was dipping by 5-6v too - a clear sign that there’s a serious short circuit going on.

It turned out to be the tail light supply wire. Not a massive shock really. Resistance between the tail lights and battery negative was only a few hundred Ohms and the wires in question were getting very hot indeed.

I also found that somebody has butchered the loom in the engine compartment to bypass a connector. Sure enough, the wire in question was black and red (the tail supply wire) and badly melted.

So I guess I need to run a new supply down to the tail lights. Not a huge hassle, surely! The odd thing is that the 6-way switch I bought off eBay a few weeks ago had a wire on it which showed signs of having been very hot. It was so badly damaged that I replaced it. Guess which wire it was… the tail light supply!

So, I can think of three possible explanations:

  1. The 6-way switch I have is somehow causing the problem. Can’t see a reason why it would, though, as the output wire from the switch is getting hot as well as the input. How could the switch cause that?
  2. Tail light problems are a common failure and I just happen to have a second hand switch from another ‘drover with a short on the tail lights.
  3. The Duke has his old light switch back!

Anyway, it’s obvious that the tail lights have caused problems in the past and somebody has tried a half arsed fix (see photo). I will have to run a new cable all the way back, I think.

Tail light cable bypassed round a connector in the engine compartment. You can’t really see it here, but the red and black tail light supply was badly melted when I got the “replacement” switch.