Trailer Wiring Harness Converter Box Failed on a 2003 Toyota Tacoma


My left side turn signal and brake light are not working. I traced the signal going into the converter box but not coming out. Can the box be repaired? 2003 Toyota Tacoma Pre-Runner

Helpful Expert Reply:

The converter box alone in a trailer wiring harness such as # 118379 for your 2003 Toyota Tacoma cannot be replaced. The whole harness would have to be replaced. Since you have determined that all of the electrical signals going in are correct but not correct on the output side of the converter this does indicate a bad converter.

But, if the converter stopped working because of a short somewhere on the trailer you will want to fix the short or the problem will keep happening. Make sure the trailer side connector is clean and free of corrosion. Inspect the trailer wiring front to back and fix any broken, pinched, or otherwise damaged wires. The main trailer connector ground and the grounds for all of the lights should be attached to clean and corrosion free bare metal surfaces.

We have a few options for trailer wiring harnesses for your Tacoma. They all install the same way: # 118379, # C55379, and # HM43315. I have also included a couple of helpful links on trailer wiring for you.

helpful expert reply by:
Michael H

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