Troubleshooting Trailer Running Light on Utility Trailer Towed by 2011 Toyota Highlander

Question:

Hello...I have a 2011 Highlander with this kit installed. Worked fine for about a year then the running lights would come on momentarily then go off. Turn signals and brake lights are fine...cant figure this out...any help would be appreciated...thanks,

asked by: Vincent D

Expert Reply:

It sounds like there is a ground problem on your trailer that may be caused by an accumulation of corrosion either on your trailer connector or the wiring to the light assemblies. I would first check for corrosion and fix as necessary.

Next, I would check the trailer connector on your 2011 Highlander for the correct voltage when the different taillight functions are applied. You would need a circuit tester like our part # PTW2993 to do this. Check out the video I attached that shows how this would be done. This will tell you if the problem is on the wiring harness # 118449 that you referenced or on the trailer side. I suspect the trailer since what you described sounds like a ground problem to me.

There is a chance that the converter box is bad on the # 118449 also, I attached an FAQ article on how to test a converter box for you to check out also.

expert reply by: Jameson C