Thread: Mystical electrical fault

G'day all!
One of the trucks has developed an electrical fault that keeps me puzzled. When flashing the high beam, the right hand side goes dim and the indicators glow a little. On high beam, all appears to be alright. The indicators work as usual. I have extra lights fitted, wired through a relay. When these are turned on, they will go dim on high beam and the relay won't disengage when high beam is turned off, keeping the lights dimming. I can uncouple the extra lights through a switch, then the situation is as described initially, i.e. the right hand side headlight goes dim and the indicators glow.
I have checked the connections and cannot find any fault. I assumed a faulty earth, but all the terminals seem fine and when I check the earth wire against a metal part of the truck I get zero resistance, indicating no apparent fault. The fuses are alright, if I pull the fuses separately, the symptoms disappear when the right headlight is inactivated (i.e. without the fuses). This indicates the trouble is somewhere on the right hand side, or not?!?
I should have added that the headlights flash without any problem when low beam is off, with low beam on, it's causing troubles.


The funny thing is, the fault is intermittent, making it not easy to figure out where the problem is located. It first appeared a while after I had the truck corrosion protected, so I assumed it was a short circuit somewhere, due to excess moisture in one of the connectors. But since it has been coming and going, driving me nuts. Should I be looking at the stalk???
The truck is an old (1989 or so) 110. Anyone an advice for me??? Ta!

Thanks, folks! I have put in an additional earth wire to the earth point at the bulkhead. Of course, everything works now. Still the question remains, where did the original fault develop? I was looking for the dodgy connection, cleaned everything I could find along the way, but the problem still persists. Does anyone know where the proper earth point should be? It is not the one on the inner side of the wing, neither the one on the bulkhead, near the fuel filter. Drives me nuts...
My truck won't be on any RAVE as it is too old, unless they did not change the connectors when the newer models appeared, but I will have a look. As for the T-shirt, I have that one already. Might be worth putting it on now, but it is still a bit chilly.
Of course, I agree I made as mistake in the head line. Sorry, mea culpa. I'll be more cautious next time. To my defense I can claim I was just coming out of the garage, completely annoyed and fed up with everything. But no excuses here, I'll get my act together and do better next time .
Cheers