Troubleshooting Malfunctioning Trailer Wiring Harness on 2009 Honda Odyssey

Updated 07/07/2014 | Published 07/03/2014

Question:

I bought this in late summer 2012 and it worked well until this spring. I now get current to all three wires regardless of whether the lights are on, turn signals are on, or even if the key is in the ignition or not. Is the microprocessor shot or is there a chance there is something else I can trouble shoot?

asked by: Greg W

Expert Reply:

According to your description, it sounds like the converter is shot, allowing output on incorrect circuits. The vast majority of the time, the failure of the converter is caused by a short circuit of some kind in the trailer wiring. Before replacing the trailer wiring harness with a replacement like the Tow Ready # 118438, you'll want to closely examine the wiring on your trailer to find the short.

If you don't locate and repair the short, you will continue to blow up wiring harnesses. You'll need to start at the connector on the trailer and examine it for damage. Then work your way all the way back to the lamps, checking for pinched wires, loose connections or cracked and worn wire insulation that would allow the copper conductor inside the wire to short out on the trailer frame. Fix the short, replace the trailer wiring harness, and you should be good to go.

expert reply by: Mike L