I have towed 2 trailers with my Defender. When I plug in the trailer plug from one of the trailers the defender recognizes that a trailer has been connected and the lights work but when i plug in the other trailer it does not recognize the trailer and the lights do not work. Anyone have any thoughts on this problem or procedures on what I can do to force a connection of the trailer to the defender?

Thank for your help

 

Do both trailers have the same type of lights? Incandescent or LED?

Have you tried both connections? IE the 7 pin and the flat pin?

Do you have a strong ground on the trailer that doesn't work with the Defender?

If using a 7 pin adaptor, do you have another one you can try? They are sensitive to LED (older ones at least)

 

Both have 7 PIN connectors. One trailer has LED which does not work while the older trailer has traditional bulbs.

 

Can you change the 7 pin connection to a new one? Is the trailer a little older? My Mercedes was a diva when it came to LED trailers. I had one 7 pin adaptor that didn't work at all and one that did.
Is the 7 pin hookup hard wired on the trailer side? Does it work with other vehicles?