Right hand (off side) side lights fuse blowing

[PetenAli]

Hi All,

We have a problem with no side lights in the right hand side front and rear. The fuse (8) has blown. I have tried isolating front and rear sidelights from each other by removing each bulb in turn but the fuse still blows. I then took out both bulbs at the same time and again the fuse blew when I switched the side lights on. So the problem is presumably not at the lights end but between switch and fuse? Left hand side works perfectly as do all other lights.

Does anyone know if there is a common place for this right hand side light circuit to short out causing the above symptom?

Thanks very much,

Pete

[1664]

According to the Haynes Manual wiring diagram (Pages 12.33 and 12.34) the fuse is after the switch so it can't be the wiring from the switch.
The first thing I'd do is visually inspect the grey/red wires to the positive of both the front and rear lamp holders for damage to the insulation or signs of chafing. There won't be too much you can trace before they disappear into the vehicle wiring harness but what length you can get at, inspect carefully.

Do you have a Haynes Manual, an electrical multimeter and do you know how to use it?

[PetenAli]

Thanks 1664 - yes, I have a Haynes and a multimeter. I've checked how much grey / red wire I can see back from the two +ve connections to the bulb holders and it all looks OK. I was just wondering if there is a place where the right hand side light circuit is prone to short out. Do you know where the cable splits after the fuse box to go front or back? If the fuse blows when both bulbs are removed the short must be before there - musn't it?

[dave friday]

Hi Peter,dont forget the wireing [and bulbs ] to the number plate light...and possibly wireing to the indicator switch.

[1664]

Hi Peter,dont forget the wireing [and bulbs ] to the number plate light...and possibly wireing to the indicator switch.

They are not supplied by that fuse so not responsible for it rupturing. Fuse 8 is dedicated to the RHS side lights and, in certain vehicles the rear ashtray and ciggie lighter illumination lamps.

[1664]

Do you know where the cable splits after the fuse box to go front or back? If the fuse blows when both bulbs are removed the short must be before there - musn't it?

Yes, fault is prior to the lamps. The cables to the front and rear lights run in completely separate wiring harnesses. As you can see from the aforementioned Haynes diagrams the circuit from S8 (fuse) runs internally to the fuse/relay box and exits at pins C14 and E18 for the front and rear lights respectively. The front wiring harness is the easiest to physically access as it exits the van behind the passenger headlight assembly and runs along the grill cross member as shown below.





Unfortunately from an electrical point of view, C14 and E18 are connected internally to the fusebox which means the only way of separating them electrically so they can be tested individually is to remove either the 'C' connector block or the 'E' connector block plugged into the rear of the fusebox. This I know from experience to be a bluddy pain as they don't exactly want to come off. So much so I'd visually inspect the front harness for obvious damage prior to struggling with the connector blocks. Anyway, the Connector blocks layout are shown below, as you can see 'C' connector is for the front wiring harness and the 'E' is for the main wiring harness. Remove the fusebox fixing screw immediately below it, lift the fuse box and gently pull forward to access the connector blocks.



Closer up



and the 'C' connector pin layout



which is the yellow block in these pictures







As you've probably gathered, my opinion is that the 'C' connector is easier to extract than the 'E' above it, but if you find the 'E' easier then pull that one instead. Once a connector is separated you can electrically test the rear and front wiring for shorts to earth individually. Pray it's the front one.

[PetenAli]

Thanks again 1664. That's really good of you to put all this info up and its making sense. Got a really busy couple of days coming up but will get onto it at the weekend and let you know how it goes.

Pete

[Mocki]

Are you sure it's not the actual bulb holders causing the short?

[1664]

Are you sure it's not the actual bulb holders causing the short?

Good point but I'm assuming they had a look at them first *crosses fingers*

If not, unplug the wiring from the lampholders PetenAli

[PetenAli]

Well, definately not a problem with the bulb holders and as far as I can see there are no cuts in the cable leading to the bulb holders. (I did find a cut in a wire going to one of the headlights so was able to fix that.)

Took the fuseboard off and couldn't get the yellow connector out much less the black one. Will have another go at it later in the week. As I was putting everything back I noticed that the tow bar electrics are wired in just in front of the near side rear light. This isn't the side causing problems but at least two of the circuits must go across to the off side (fog light and indicator) and also one connection operates both tow bar tail lights - so something could be up there. Its wrapped up in several metres of insulating tape so finding out what's underneath that lot could be illuminating (sad pun).

This is going to be one to keep plugging away at - like most things on our van it will fight to the bitter end.

[1664]

I'd disconnect any tow bar wiring next then.

Told you those fuseboard connectors were a bitch Push comes to shove disconnect both batteries, push connector tabs together and try and lever off with a flat edged screwdriver.

Tow bar electrics first though

[PetenAli]

FOUND IT!!

It was the connector for the tow bar wiring. Traced the brown wire from the 7 core cable into the loom where it was hidden under several feet of gaffer tape. It was connected by a scotch lock. I just removed that, insulated the grey/ red wire in the main loom, put a new fuse in and it all worked! It actually took me longer to empty all the camping gear out of the back, remove the engine lid and remove the n/s light unit than it did to find the problem this morning.

Going to solder in the brown wire and heat shrink insulate the soldered joint. Also check the circuit from where the brown wire is soldered in to the tow bar socket. Then I'll check the rest which are probably scotch locked as well.

1664 - thanks very much for all your help and patience which is very much appreciated and which has helped me to learn some more. I've still not managed to get that yellow relay plate off but will save that for another time now!

Pete

[1664]

Excellent

That's the trouble with Haynes Manuals, they don't show tow bar and/or DIY wiring.

[Mocki]

I'm pleased you have sorted it
I think that this thread is a perfect example of why it is important
to give all the details when posting up a problem for solving.
You need to remember we cannot see what you can and I'm quite sure that
if you had mentioned the towbar at the beginning it woul have been a very
much shorted thread and solved much sooner !

Have fun!!

[PetenAli]

I'm pleased you have sorted it
I think that this thread is a perfect example of why it is important
to give all the details when posting up a problem for solving.
You need to remember we cannot see what you can and I'm quite sure that
if you had mentioned the towbar at the beginning it woul have been a very
much shorted thread and solved much sooner !

Have fun!!

Message received!! To be fair I hadn't made the connection (another sad pun ) as previously the trailer lights had all worked.