Rv wiring stumper????

If I understand what you’re saying, there are four wires from the tow vehicle to the trailer. I don’t recall the color but the wires are: ground, running lights, right turn/brake light, left turn/brake light. The problem is that vehicles built after about 1992 have separate brake light wiring, and turn signal wiring, thus requiring more than four wires. One alternative is to upgrade to a 7 pin connector such as used with larger travel trailers, or install a device to combine the brake and turn signal functions to two wires. The first options would allow full functionality identical to the tow vehicle. The second would use the turn signal for brake lights. I use the 2nd option for my jeep that I tow with the motorhome using some diodes (actually 1/2 of a full wave bridge) to feed the rear lights on the jeep. The link shows some of the devices that can be used to combine the stop and turn signal lamps.


http://accessories.etrailer.com/trailer/Brake%20Turn%20Light%20Converter