Rear lights keep popping the fuse

[Gadgetborder]

Hi All,
Just joined the club and forum as I bought my new Bongo a few weeks ago. This is my first post and unfortunately it’s a question about a problem rather than anything nice I’ve done yet to convert the van. It’s currently unconverted.
He is a 1997 2.5 diesel.
I am slowly ticking the jobs off. I have just had the cam belt and service done. I fitted Van-x rear curtains (which are really nice).
I don’t think it is related to any of the work just done but my rear lights are not working. When I change the fuse (15A) under the bonnet and turn the lights on I get a split second of the sounder as the door is open and then the fuse goes.

I have tried the wiring diagrams in the members area but I can’t see them as you need flash and it is no longer supported/available so I was wondering if anyone knows the key interface points between harnesses and where they are so I can take sections of the circuit out of the equation to help me pin-point the area of problem?

Any help would be appreciated before I rip the whole car to bits. Apart from that everything else works!

Thank all

Wayne.

[Northern Bongolow]

From memory the wiring loom for the back end goes along the driver's side panel where the grab handles are then into the rear door, is it possible you may have drilled the wires while fitting your curtains.

[Gadgetborder]

Thank you for that. That was my suspicion. So I just got back in from my 20th trip out to the van to check something else and mysteriously it is all working again. I can only think I disturbed something that was causing a problem. I only flipped back the passenger seat and fiddled with the back lights but couldn’t see any problems in either area!.

So to save everyone time don’t worry about locations for now.

If it reoccurs I will let you know. Or if I find the issue I’ll post it on here for future reference to help anyone else out!

I think it’s taunting me to see what I’m made of!!

Thanks

Wayne.

[Gadgetborder]

Hi all again,teh Bongo has been away a while for welding!! enough said there.
my rear light problem has resurfaced, the garage, unknown to me, popped a 20aA rather than 15A fuse in there and they have stayed on. When I put a 15A in there it pops again.
It seems to have LED headlight bulbs fitted with what looks like Ballast resistors before the bulb.
Not sure if this is a known thing?
Its almost like there is a resistive short somewhere that causes 15A to pop but not 20A.
I need to trace wiring and circuits as the relay clicks when I pop sidelights on. I would have thought they are low enough current to not warrant the relay but I need to trace circuits next I think.
I have tried to look up the fusebox factsheet in the members area to be told that I don't have permission. Everything else in there works so I don't know if that is just a broken link but is there anywhere I can find a circuit diagram for the car or at least the lighting circuit. Happy to buy one if anyone knows where to get them from otherwise I may have to rip out the lighting wiring and start replacing it all until I find the problem.

I have also discovered that with a 20A fuse in my interior illumination is:
Cluster
Recirc button on climate panel
Front Defrost button on climate panel
Front fog light switch
LH blind switch

Also the interior light are on very, very dim when I turn it all off and leave the car.

It is baffling.

Everything else is off from a switch illumination point of view, not sure what should be lit on the climate panel but I assume everything!!

I am wondering if there is some fault on the illumination circuit that is causing a rusty short or something similar?

If anyone has experienced similar I would love to know what they found or any advice.

Once I have sorted this I will Ask about solar, EHU and Ecoflow connection but that can wait.

Thanks for any advice in advance.

Cheers

Wayne

[g8dhe]

Using LED's will cause all sorts of problems, for the headlights MoT failures if the garage actually look at the light beam, internally the switches and wiring aren't designed for LED's hence a few microamps leakage causes the LED's to remain glowing no easy answer although leaving one filament lamp per switched circuit working will solve some problems.

[Gadgetborder]

Thank you Geoff, i am going to rip the LEDs out and revert to normal lights.

I managed to find the wiring diagrams using a friends windows laptop as I only have mac and managed to download the Chinese browser.

I think I needed circuit diagrams. I will rip the LEDs out first and see what happened then. I’ll whip out the climate panel and see if its just bulbs gone too and then take it from there.

Thanks for the help.

Wayne.

[Gadgetborder]

Hi all,
Well, lights have been fine with 20A fuse in for now until i could get around to sorting it.

LED lights have gone and back on halogens.

Tried to look at it all yesterday and the lights are working fine again now, even with 15A fuse fitted.

However, the brake lights are now popping the fuse whenever I touch the brake.

Interior light is not on dimly anymore. I have dropped rear lights out of the circuit and it still pops.

Stripped put trim and headliner and all wiring to rear looks good.

Is there any commonality (except earth) that could be causing this between the brake and side light circuits.

Next step is pretty much stripping the dash out and tracing each wire.

Its driving me nuts.

Cheers

Wayne.

[g8dhe]

Have you had any work carried out, welding, rear aircon, do you have a conversion, the wiring loom runs down the offside so any work carried out on the offside may have damaged the loom. Another possibility is the earth returns via the chassis can be affected by rust causing problems.

Uprating fuses is never a good idea, they protect the wiring, not the device on the end of the wire, from short circuits, you run the risk that the wire gets hot and damages the insulation ....

[teenmal]

It might be worthwhile checking the brake light switch.

[Gadgetborder]

Hi Geoff, thank you for the reply.
The problem was there before any work was done. Had new inner and outer sills fitted.

The earths were my next port of call just in case its getting some random back feed path.

I can only work on it for bits of time in one go due to other commitments. I have rewired the trailer light wiring properly getting rid of all the scotch locks on the harness and soldering, heat shrink sleeving and sealing.

I will check brake switch but as the problem moves from rear lights to brake lights I suspect this is fine and when failed they pretty much bring the brakes on continuously or not at all.

The fuse uprate was something the garage did and it shocked me to see that it didn’t cause a problem, although it does suggest a resistive load to be the problem so grounds my be a cause. It now has the original 15a fuse in and works fine.

I’ve pretty much stripped everything out of the back to see all the wiring and thats all good. I am worried it is on the engine or behind the dash where the problem lies!

Going to draw out the brake circuit from the wiring diagrams on here and see what exists within the brake and lights circuit in therms of common areas that could cause a failure in other circuit.

I will update if I find anything .

Thanks again for the ideas.

Wayne.