Troubleshooting a Tow Ready T-One Harness on a 2007 Dodge Durango

Question:

We installed the harness to find that when we used the left directional nothing happened. Right directional caused both taillights to blink. Headlights on, the trailer lights did not go on. Installed as per the video, could this be a backward unit. Should I try reversing the harness wiring?

asked by: Michael S

Expert Reply:

It sounds like there is a ground issue on the trailer. If you can I would try connecting your trailer to a different tow vehicle that you know works correctly to verify that the problem is in the trailer or the tow vehicle.

The reason I think it is a ground problem on the trailer is because you said that when you switch on your headlights the trailer lights quit working altogether. That is usually a dead giveaway for a ground problem. What usually happens is that the lights will work to a certain degree, but when the running lights are on and there is a larger draw on the circuit it becomes too much for the weakened circuit and everything quits working.

I would recommend you take a look at the grounds of your trailer lights to see if there is any corrosion, frayed or exposed wiring, or anything else that looks problematic and fix as necessary.

I would first check the wiring of your trailer before you attempt to reverse the wiring of your harness # 118390. I do not believe that would fix the problem since the problem you described is not just a matter of the blinkers be switched on the trailer.

You should also check for the appropriate voltage on the 4-way with a circuit tester like # 3808, this will determine if the 4-way is functioning correctly. Check out the video I attached to see how to do this.

expert reply by: Jameson C