Tow bar electrics
Discussion
I’ve just fitted a PFJones dedicated wiring kit to my mK5 golf, it runs via the cars canbus system, I’m 99% sure I’ve got all the wiring correct, there isn’t much to be honest, power, earth and a couple of wires that connect into two canbus wires in the car.
I plugged the trailer into it and the lights come on with the car as they should, I don’t have brake lights on the trailer, and when you indicate, left, right or hazards, the main lights on the trailer flash. The car lights all function correctly with the trailer connected.
I haven’t coded the ecu yet but I believe this just tells the car when a trailer is connected so it alters the ESP.
I’d really like to use the trailer this week and have limited time so could anyone think where to look first?
Could a trailer bulb cause this? Could I possibly have wired the socket wrong?
The erde trailer is almost brand new but I haven’t seen or got the option to plug it into another vehicle to check it.
TIA
I plugged the trailer into it and the lights come on with the car as they should, I don’t have brake lights on the trailer, and when you indicate, left, right or hazards, the main lights on the trailer flash. The car lights all function correctly with the trailer connected.
I haven’t coded the ecu yet but I believe this just tells the car when a trailer is connected so it alters the ESP.
I’d really like to use the trailer this week and have limited time so could anyone think where to look first?
Could a trailer bulb cause this? Could I possibly have wired the socket wrong?
The erde trailer is almost brand new but I haven’t seen or got the option to plug it into another vehicle to check it.
TIA
I've done a couple of canbus towing electrics set ups and as you have found they do make for a nice tidy installation OP.
Light weirdness can be the result of a bad 0V connection somewhere. Have you got a multimeter? If so, check resistance between everything on the electrics installation that's meant to be at ground, and everything on the trailer that's meant to be at ground, then finally with trailer connected check resistance between trailer lights ground and the car ground.
ETA just saw you said you wired the socket - is it possible you've got your ground wire(s) in the wrong places? Kits I've done had the socket prewired at both the trailer connector and the interface so that's not a step I've ever had to check!
Light weirdness can be the result of a bad 0V connection somewhere. Have you got a multimeter? If so, check resistance between everything on the electrics installation that's meant to be at ground, and everything on the trailer that's meant to be at ground, then finally with trailer connected check resistance between trailer lights ground and the car ground.
ETA just saw you said you wired the socket - is it possible you've got your ground wire(s) in the wrong places? Kits I've done had the socket prewired at both the trailer connector and the interface so that's not a step I've ever had to check!
Edited by donkmeister on Friday 28th October 23:24
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