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Trailer electrics issues
daniel mason - 19/5/16 at 05:15 PM

Having a few issues with the trailer electrics/ VW van!
After 12 months with no issues I suddenly lost left indicator on the way back from Anglesey a few weeks ago which I assumed was a bulb as everything else was fine.
So I Hooked the trailer up to another car and everything was fine.
So I hooked the van up to a different trailer and lost right indicator but left was working?
I have one of those small trailer wiring units at the rear of the van which beeps when indicators are on. But when one or the other side doesn't work it just clicks with no beep and the other side works as normal.
Any ideas where to start as I've not even had time to look at it yet? Cheers


lsdweb - 19/5/16 at 06:13 PM

Check the earth(s)! Try running a cable from the earth terminal to a known good earth on the van.

Wyn


gremlin1234 - 19/5/16 at 06:21 PM

quote:
Originally posted by lsdweb
Check the earth(s)! Try running a cable from the earth terminal to a known good earth on the van.

Wyn
also check the earthing on the 'beeper box' in the boot.


rusty nuts - 19/5/16 at 06:28 PM

Check the terminals inside the 7 pin socket on the car , you'll probably find the terminals have corroded. Common problem with tow bars


daniel mason - 19/5/16 at 06:42 PM

Thanks for the advice,I'll check over weekend


bi22le - 19/5/16 at 06:42 PM

I would check inputs to the flasher box and outputs from the box, at the box.

My bet is on the box if it is a cheap aftermarket one.


daniel mason - 19/5/16 at 06:53 PM

It came with the towbar and is a universal type.so it could well be this unit failing but I'll check it all out


snowy2 - 21/5/16 at 06:05 AM

tow bars are often fitted with scotchlocs.......these are the devils work they are often the cause of many electrical faults on cars (even when the wire has been removed but the scotchloc is left in place. if your car has had them used in the fitting of the tow bar...REMOVE THEM AND MAKE THE CONNECTIONS PROPERLY....

That will cure most faults with tow bars.......(I used to fit them and fix them as a mechanic, after a while you stop using scotchlocs to save the hassle of the faults that keep on coming back.

when removing scotchlocs, ensue the wire where they were fitted is in good order as the corrosion at the point of contact can cause a high resistance spot on the wire and will lead to weird faults where continuity will be found on the wire but it wont carry any current so the lights wont work......

if its not fitted with scotchlocs your likely looking at dodgy earth’s...


blue2cv - 21/5/16 at 07:29 AM

Just clean and spring terminals in socket and plug, if fault is diff from trailer to trailer or car to car its hardly a moving wiring fault, plugs and socket corrode and the split pins close losing contact