Magnetic Flat Towing Tow Bar Wiring Kit Flashes Both Turn Signals Instead of Just One

Question:

Im trying to wire a set of magnetic tow lights to motor home so I can pull my little Suzuki behind. The 4 wire flat plug that came with the set of towing lights came loose and ground off nearly every bit of the plug leaving no clues how it would have been wired, so Im trying to wire it to the 7 pin pigtail connector on the back of the motor home. The four wires on the tow lights are red, white, green, and yellow and goes to the first of the lights, but only green, white and yellow go to the second light. My question, everything I read indicates four wires should be brown, green, white, yellow. But my set has red instead. Ive attached green to right signal connector, yellow to left, white to ground. Ive substituted the red for brown to the running light connector on the 7 pin pigtail. Running and brake lights work, but with either flasher Im getting both lights flashing. Where am I going wrong?

asked by: David C

Expert Reply:

On a 7-Way, just as a 4-Way, the turn signals and brake lights are combined on the same circuit on each side. So yellow is left turn and brake, green is right turn and brake, brown is running lights, and white is ground.

Usually when there is a red wire it is brake lights. But on a combined system like this the brake lights should be combined with the turn signals.

There could be a short that is causing both turn signals to activate at the same time. You will want to inspect the wiring and the connections and fix any broken wires or loose connections. Also check for corrosion that could cause a short. I believe that you are correct and the red should be running lights but if you disconnect it and the problem stops then it could be that the light kit you are using is designed for a trailer connector that uses separate brake lights and turn signals.

I have included a link to our help article on wiring that shows how the various types of connectors are wired. You will want to make sure that your RV 7-Way matches because a different wiring configuration could cause some problems like this as well.

expert reply by: Michael H