New to the forum!

Looking to get some assistance. I had a towbar and dedicated electrics fitted (ECS wiring loom), but in order for this to work. I need to have this the trailer/towbar function activated to detect the the new loom.
Not sure if there is a friendly local who can help do this or happy to take it to a specialist that knows how to do this.
Tried a couple of places with no luck and really don't want to go to the dealer!