Hi folks, a most odd thing has happened, the rear fog lights and brake lights on my 2003 Ducato camper have somehow changed places!

When the fog lights are switched on the brake light filament comes on instead, when the brake lights are actuated by the pedal the fog lights come on.

Also the fog lights (now the brake filaments) do not now go off when main beam is selected.

A 7 pin trailer socket is fitted using a dedicated wiring kit, the trailer brake lights lights and fog light work as they should, except that now the fog light does not go off when main beam is selected.

I have tried unplugging the trailer wiring and putting back the original, and cleaned all contacts to no effect, the problem remains.

I have no way of knowing how long there has been a problem, as the camper is not used often, it was only noticed when tracing a faulty trailer side light and the yellow wire in the socket was found to have pulled out, both 5 amp side light fuses (passenger side fuse box) where blown and replaced in the process of fixing this. The vehicles fog lights go off as they should when the trailer is connected.

Thanks for reading this far, any pointers would be very helpful as I'm a bit lost with this temperamental modern stuff!

Bernard

Hi
I would be looking at the wiring earths on the vehicle itself as it seems that the fog & brake lights are earthing through each other. This would seem to be reinforced by the fact that the foglights go out (what about the brake lights?) when the trailer is connected which means the earthing from the trailer back to the vehicle is correcting the bad earth & is using the trailer wiring when it is connected.
Cheers

Hi FreeSpirit, Thanks for that, I hadn't thought of an earth fault because usually I find (with trailers, may be different on the vehicle though) an earth fault causes the affected bulbs to glow less brightly, but both vehicle and trailer brake and fog lights are as bright as normal.
Will check it tomorrow. thanks

I have a slightly different problem - I have the orange warning light appear when my rear fog is switched on and my rear fog doesn't work!

I've checked all the bulbs, switched the back lights around (all bulbs flashed indicating that all sockets work) and I also checked the fuses in the engine block, so I imagine that this is an electrical fault?
My question is any idea what and how costly?

Any estimate on what a garage might charge me for inspection / what the fault could be. All other lights and anything electrical works in my car.

Any help would be appreciated!

Why do you think they have swapped places, which positions are they in? The fog light bulb (21W) is also the tail light bulb(6W), the brake light is a 21W bulb further up the lamp. Are you saying your stop light has moved to join the tail light bulb?
Does your tlr skt have a microswitch in it? if so, this will turn your van rear fogs off when a tlr is attached so your don't get fog light glare off your trailer into your rearview mirrors.
Twizzles, what model vehicle do you have? Can you hear a relay click in when you turn rear fog switch on. If bulbs and fuses are ok, check the plugs to the lamps, check your trailer skt.

Had a similar problem on mine over the last couple of days.
I repaired it to-day. found a bad earth contction at the multiplug that plugs into the light cluster n/s/r.

Arkk said:

Why do you think they have swapped places, which positions are they in? The fog light bulb (21W) is also the tail light bulb(6W), the brake light is a 21W bulb further up the lamp. Are you saying your stop light has moved to join the tail light bulb?

Click to expand...

Thanks very much for that, you have of course hit the nail on the head!!

Looked it up in the book and there it is 'Rear fog light/tail light' bulb

I have never seen this arrangement on any vehicle before, to me a stop/tail lamp is exactly that, not a fog/tail lamp. The only reason I looked at the lights at all was because I blew the fuses, and that sent me off chasing all sorts of red herrings..

Sorry for the delay in replying, but as the lights still worked OK I hadn't bothered to do anything about the problem, just as well really!