Trailer Wiring Harness Troubleshooting and Recommendation for a 1994 Mazda B-4000


I have a 1994 Mazda B-4000 pick up.Just want to make sure this is the right one for my truck. I recently bought a magnetic tow light kit for my truck and I hooked it up and I had tail,brake lights and a right turn signal but no left one.I probed the wiring with a electrical tester and have no power to the yellow wire. I have a Hoppy electric taillight converter on it now that I bought about eight years ago,the only numbers on it are 310-0041-560 on converter on the T part numbers are 4021/3021. I am guessing this part is bad and I need another,if so is this one you have listed here the one? 118325.....

Expert Reply:

The Tow Ready T-One Vehicle Wiring Harness, # 118325, is the correct wiring harness for the 1994 Mazda B-4000. It provides a 4-pole flat trailer connector for your vehicle.

It connects to the taillight wiring harness along the inside of the left rear frame rail. This harness will have a connection point with connectors matching the ends of the T-connector adapter.

You might want to also check the yellow wire going into the converter to see if you are getting power going into the converter. I would recommend you get a Circuit Tester # 3808 for this. If you have power going in to the converter but not coming out then the converter would be bad.

You should check the wiring on the trailer for an electrical short before you attach the new converter. If there is an electrical short on the trailer, then that could cause the converter to go bad. You will want to get that repaired before using the new converter.

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