Any Trailer Electric Experts Here?

[Littleblackflash]

I fitted a PF jones trailer electric kit to my van a year ago and it's been working fine. I've not used it for a month whilst I sold my trailer and brought a new one. When I picked it up I checked the lights and they all work except the brake lights which are on 100%.

I've checked the module today with VCDS and it's not reporting any failure codes. On the module their is a green light which indicates the CAN bus is connected and all working. It's not a fault with the trailer because it happens on both my trailers and I have 12v on pin 6 of the socket.

On VCDS I though I would check the inputs.


But despite all of the other lights working, the actual figures remain off all the time.

Do I have a duff module?


I need the trailer next weekend so I need to fix it quick, or I'll run a separate wire from the tail light to the socket to get me going.

 

[Johnod17]

Is it the trailer or the van at fault
Have you another trailer board or tester to plug in ?

 

[Littleblackflash]

Clearly the van at fault. The trailer is brand new and my other trailer has same fault.

I should only get 12v on pin 6 when the brakes are on so the fault is with the van.

 

[Pauly]

If its only trailer brake lights on and not vehicle brake lights then cant see what else could cause that other than issue with the control module ?

Think i would try a battery disconnect, sounds almost like the relay in the module is stuck on ?

 

[Littleblackflash]

The van brake lights work fine, its only the trailer brake lights on 100%. Good idea to disconnect the battery, I'll try it tomorrow.

edit.
Thinking about it, I've already disconnected the module and reconnected it. Still the same problem.

 

[Littleblackflash]

The technical line at PFjones came to the help.

There are only 3 wires to connect, 2can bus wires and a brake line feed. The brake line feed is only needed for the stability control so if you only have the 2can wires connected, the light should all work (inc the brakes).
When wiring in my tailgate, I noticed the brake line cable wasn't connected, but it was clear where it used to be. So I reconnected it (wrong thing to do).

The brake line feed is a red cable with black trace, and mine was connected to the BCM red cable with black trace. This is actually the BCM power feed, I should of connected it the Black wire with Red trace.
Now it's connected right, it all works.

 

[Rob78]

The technical line at PFjones came to the help.

There are only 3 wires to connect, 2can bus wires and a brake line feed. The brake line feed is only needed for the stability control so if you only have the 2can wires connected, the light should all work (inc the brakes).
When wiring in my tailgate, I noticed the brake line cable wasn't connected, but it was clear where it used to be. So I reconnected it (wrong thing to do).

The brake line feed is a red cable with black trace, and mine was connected to the BCM red cable with black trace. This is actually the BCM power feed, I should of connected it the Black wire with Red trace.
Now it's connected right, it all works.

Yeah I’ve got the some problem, I could if fine a black/red wire under the steering wheel only found red/black so connected to that one and brake lights on all the time
What do I do if I can’t find the black/red wire???

 

[Littleblackflash]

The black / red wire is on the BCM connector, not behind the steering wheel

 

[Deaky]

Yeah I’ve got the some problem, I could if fine a black/red wire under the steering wheel only found red/black so connected to that one and brake lights on all the time
What do I do if I can’t find the black/red wire???

Red with black trace is permanent (timed) +ve from the courtesy light circuit.

Brake lights (Black with red trace) are Pin 16 in the white connector on the BCM, it also passes through Pin 1 on the light green connector under the left front seat and also Pin 8 on the black connector under the roof trim near the left D pillar.

 

[Jimbobadini]

The technical line at PFjones came to the help.

There are only 3 wires to connect, 2can bus wires and a brake line feed. The brake line feed is only needed for the stability control so if you only have the 2can wires connected, the light should all work (inc the brakes).
When wiring in my tailgate, I noticed the brake line cable wasn't connected, but it was clear where it used to be. So I reconnected it (wrong thing to do).

The brake line feed is a red cable with black trace, and mine was connected to the BCM red cable with black trace. This is actually the BCM power feed, I should of connected it the Black wire with Red trace.
Now it's connected right, it all works.

Thanks!
You saved me a massive headache had exactly the same issue. Snipped the wire all sorted. The PF jones instructions are pretty terrible, wouldn’t care but took me ages to connect that wire upside down in the footwell!