Troubleshooting Seven Blade Vehicle Side Trailer Hook Up with Constant Power to Right Turn Signal

Published 08/10/2018

Products Featured in This Question

4-Pole Trailer End Connector

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Dielectric Grease for Electrical Connectors, 2 oz.

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Reese Multi-Plug Wiring Harness for Factory Tow Package - 7-Way and 4-Way Flat Trailer Connectors

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Curt Powered Tail Light Converter w/ 4-Way Flat Trailer Connector and Install Kit

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Hook Probe Circuit Tester

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Question:

Thank you for your reply. The blade seems fine and there is zero corrosion. Besides the seven pin/blade connector, my truck Also has a four pin connector which has the same symptoms. I checked all the fuses and I now wonder if it is possible if there is a faulty module. I don’t even know if there is a controlling module.

asked by: Chuck T

Expert Reply:

Your right turn signal and brake blade are right next to the 12V power on your 7-way. It is not uncommon at all for corrosion or debris to cause a connection between these blades that would cause exactly what you are describing of a constant power on that blade.

I recommend using some sand paper and an old toothbrush to really clean those blades and then use some dielectric grease # 11755 to keep the moisture, corrosion, and debris from happening in the future. If cleaning your blades does not solve the problem, then disconnect the trailer connector and test the US Car Connection directly behind it for functions using your circuit tester like # PTW2993. If that is good, then replace the trailer connector with a compatible connector like # 74682.

expert reply by: Jason S

click to enlarge

Chuck T.

8/10/2018

Jason S.

8/10/2018

Since you have a 4 way connected with the same symptom, I recommend disconnecting the round factory US Car connector and testing the functions there. If the symptoms are not present there, then replace your 7-way and 4-way connector at your bumper. If the symptoms are present there, then you will want to use your circuit tester # PTW2993 to probe through the insulation on that right turn wire every few feet to see where the short is taking place. If you can't find it, I recommend taking to a mechanic to check the wiring as I don't have access to a full wiring schematic. If you decide you want to avoid that since everything else works, you can splice in the Modulite # 119147KIT for that function.