Troubleshooting Trailer Turn Signals that Both Flash when Either Turn Signal is Activated

Question:

I bought the tekonsha t one connectot for my 03 durango. Iinstalled it and everything works except my turn signals both flash when using my turn signal. Please help.

asked by: William H

Expert Reply:

I recommend we start by testing the 4-Pole connector on the # 118381 harness. You can use a circuit tester, like # PTW2993, to test the pins on the connector for each function. This is easiest if you can have a buddy sit in the vehicle and signal the lights while you test for the functions at the connector. I have attached a video showing how to test a 4-Pole connector for you.

If the connector doesn't test for the proper stop, turn, and taillight functions, then you will want to check the wires on the harness to see if any of them are cut, pinched or damaged that could be causing your turn signal issue.

If the connector tests fine, then we know the issue is on the trailer's wiring. You will want to check the wiring of the trailer for an damages, tears, pinches, or cuts. This is the same principle as checking the wiring harness. If there are wires that have been exposed and they are touching metal or another wire, this can cause the turn signal circuit to short and misbehave.

Any damaged wiring will need to be repaired. You can cut out the damaged section and install a new section of wire. For the turn/stop/tail wires, you can use 16 gauge wire like Bonded 4 Wire # 16-4B-1 or Primary Wire # 16-1-1, both of which are sold by the foot.