Towbar lighting

decj15

trying to wire a light socket on a transit connect 2015 and was told I would need a bypass relay so purchased one with the new towbar. its a (teb7as) and according to instructions and diagram if the brake and tail on your vehicle are wired together you only need to connect the red brake wire from the relay and tape back the black and brown tail light wires. when I do this I can only get brake lights on trailer and no tail lights and if I connect black and brown wires the brake and tail lights stay on constant. indicators are working fine so presume the relay box must be ok and the problem must be with the idiot writing this. can anyone enlighten me???

colm_mcm

I think they mean the brake and tail being on one single filament bulb with variable current going into it as opposed to being separate circuits on a dual filament bulb. Make sense?

decj15

That's why I then tried to wire in the black and brown to tail lights but then both brake and tail on the trailer stay lighting.

colm_mcm

Are you sure you have brake and tail the right way round? I assume it’s all one bulb on the trailer?

decj15

Yes all one bulb. I have tried a few scenarios with wiring if i switch the brake light red wire i get a bulb fault on the dash so presume i had it right way round. Lost!!!

colm_mcm

decj15 wrote: »

Yes all one bulb. I have tried a few scenarios with wiring if i switch the brake light red wire i get a bulb fault on the dash so presume i had it right way round. Lost!!!

Is there two filaments on the bulb on the trailer?

decj15

sorry yes 2 filaments

colm_mcm

And the van has 2 filaments too. Def a wire in the wrong place or a bulb not in the holder correctly by the looks of it.

decj15

I will have to give it another try the weekend see if I have missed something but was beginning to think its a relay problem or compatibility issue. will let you know if I get it sorted thanks again