Left brake and left turn signal not working on tow vehicle

We had a similar problem with our 2006 Phaeton on a Freightliner XC Chassis in early 2007. We have a module in the rear passenger side compartment that drives the toad light system, we lost the turn signal and brake light on the passenger side. I tapped into the motorhome's passenger side turn signal at the tail light and added a wire to the back side of the 6 connector plug. This solved the problem until we had the complete module for towing changed out.