I still haven't sorted my wiring out yet, some little niggles I think the same as your having (gdw wiring kit)
1. When the adapter is plugged in the indicators flash really fast.
2. When the trailer is plugged into the adapter the indicators flash fast.
3. Failed MOT for rear fog light not working due to tow bar electrics.
Solutions:
1. Unplug the adapter when not towing.
2. Dont use a trailer with LED lights as the control box looks for normal bulbs
3. The kit is designed for European A2s where the fog light bulb is on the other side of the car. If you look at the link harnesses you had to plug into each light cluster you will see that the divers side link has 4 pins but the original loom has 6 so two are missing (for the fog bulb that's there). And on the passenger side there are 4 pins on the original loom but the link harness has 6 pins (for fog light bulb that isn't there). I'm planning to convert the rear fogs to have a bulb on both sides and add the necessary wires.
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