2011 35d trailer electrical system
 

Has anyone had a dealer successfully install the OEM brake controller, wiring harness and hitch receiver on a 2011 X5?

The dealer can't get the installation to work properly on my 2011 35d. They've been working on it since early summer. It's been a brutal process.

Everything appears to be working now except the circuit that allows the car to charge the trailer battery. Anyone have any ideas on how to fix this?

Thanks.

Mine has been installed but I haven't had a trailer on it to check.