Hi LZ.
I just got a used Disco 4 2011. Had it for at week but to day when i pluged in a trailer, first the brake lights were constant on, on the trailer and the left side tail lights whent out, they stayed turned off until we turned off the car, removed the trailer cord and turned the car back on.

So we drove to a shop, where they tried with at test light bar, and pluged it into the car, which resulted in the left side tail lights now are shut off regardless off the ca being turn off and back on?

The brakelights work in both sides and so does the reverse lights.

Have anybody tried the same problem as this?


Thanks in advance.

Martin

I do not know on the D4, but D3 with trailer sockets has all the fuses in the left rear cubby hole, pull the fuses and try the lights again.
I would be looking inside you trailer socket for water ingress or corrosion.

I found a fuse under the glove-compartment, that was blown, so now the lights on the car works again.

But i still need to find out why it lights up the brake lights, instead of the normal lights on the trailers ;-/

It looks like the trailer socket is connected correct (wiring).

If trailer has led lights that could be your issue.
Have a look on disco4.co.uk forum. Plenty of discussions for this.