Troubleshooting a Trailer that Taillights, Blinkers Both Flash and Only One Running Light

Question:

We have a 2013 f350 super duty with a reading bed. We need to rewire our trailer plug it is a Pollack 7 way plug. the trailer is wired correctly b/c it works on our other 2 ford trucks but when we plug in this truck the driver side running lights do not come on and when you turn on the right turn signal they both flash. So is there a way to take apart the plug it self and fix it or what would we need to do?

asked by: Amanda

Expert Reply:

It sounds like the problem is the wiring of your truck like it sounds you have determined already.

What I would do is use a circuit tester like part # PTW2993 to test the circuits of your 7-way while a buddy applies the different taillight functions. Use the diagram I attached to the right for more info.

The problem could be as simple as corrosion on the connector that needs to be cleaned off (inside or outside of the connector), or it could be that the wires of the connector have shorted out to each other.

expert reply by: Jameson C