Tow bar wiring help

[Cataldoodledoo]

Hi, I have the below tow bar and just need help deciphering the wiring.

I have two looms going to the left and towards the black box in the engine bay, and one red wire going to the rear drivers side light.

Any diagrams/instructions around?

Thanks!

[Robsey]

That red wire looks like an after-thought.

Possibly a split charge wire for a caravan leisure battery. If done properly, it should be controlled via a relay.

Or perhaps a rear fog cut-out circuit...

The wire colours for the rear light clusters are...

This is the white barrel plug in the junction box.
T7/1 = Black / White for left indicator
 T7/2 = Black / Green for right indicator
 T7/3 = Black / Red for both brake lights
 T7/4 = Grey / White for the rear fog light
 T7/5 = Grey / Black for left tail light
 T7/6 = Grey / Red for right tail light
 T7/7 = Brown for chassis / earth for both rear clusters.

and then there is the separate black / blue wire for the reverse light.

There may be a mechanism on the rear fog light wire to prevent it lighting up when a caravan is hitched up.

If it was me, I would want to look inside the connector boots to see where the red wire actually goes.

[Cataldoodledoo]

Red wire goes to the rear left indicator, posted on another thread by accident!

Hoping I can get rid of it and use the main looms going from each of the tow sockets.