Hi, I recently fitted LED lights to my trailer only to find the old girl won't register them because of the Canbus so I have tried fitting a towing bypass relay as suggested. The issue I have is the wiring from the FoMoCo TTP to the 13 pin socket, I can't find a wiring diagram anywhere and using common sense doesn't seem to have worked so I'm totally stuck, any ideas would be appreciated

I thought you could get LED bulbs that dont upset the canbus and were a direct replacment for the original filament bulbs. Maybe Im wrong.

I had a open circuit somewhere on my trailer and tried finding it by simply connecting the trailer to the car to power the circuits and wiggling bulbs and wires but I got very confused because the car kept shutting the circuits every time I shorted something - even catching the bulb base whilst removing and inserting was enough to shut down the circuit. In the end I resorted to connecting in a spare 12v battery and testing each circuit separately. Paper clips work well on the pins on the trailer plug. Jules

I think you’ll find the car is not registering them because of the change in resistance that LED’s have (using significantly less power )...

I had the same on our HGV when I changed the rear lights to LED ones... I cured the problem by fitting a number of resistors across the bulbs....

You might need one of these:

https://www.ebay.co.uk/itm/Trailer-Caravan...3142020908 Andy
Freelander2 HSE (59 Plate, MY10 spec)

Thanks for coming back to me, I've tried the LED bypass box but ended up taking it out as the wiring doesn't make sense and didn'tthe trailer socket work but I have found an in line unit that plugs into