Problem adding Electric Brake Controller. on 2000 Ford E-350

I have a 2000 Coachman Catalina Sport Class C motorhome, built on a Ford E-350 chassis, prewired with towing package. I added an Electric Brake controller, but when I connect it with the Ford adapter cable into the prewired plug under the dash two things happen: 1. Right turn signal comes on and stays lit on dash and front turn signal. The right rear turn signal stays dark. 2. No power or 'Error Message" indicated on Brake Controller. Any suggestions as to where to look for a problem?

Asked by for the 2000 Ford E-350
I have the exact same problem and was wondering if you have found a solution to the problem?
Further research into the issue identified this as a common problem in this model unit. I decided it would be easier to wire the RV myself rather than troubleshoot the existing prewiring. I ran new wire from the battery as well as new wire from the rear plug; fished both through the firewall and connected them to the controller. I spliced into the brake pedal wire and connected it. All worked fine and only took a few hours. Your welcome to contact me directly at