7-Way Trailer Connector Not Working on 2004 Nissan Titan  

Question:

Expert Reply:

The Tow Ready Replacement Multi-Tow 7-Way & 4 Pole Trailer Connector # 74682 that you referenced is intended for the Nissan Titan that is equipped with the factory tow package. If your Titan came from the factory with the tow package it should have the necessary relays and fuses in place to activate the trailer harness.

If only some functions work, but not others such as the left turn light for the trailer, then there may be corrosion on the connector. I suggest you use a circuit tester like # PTW2993 so you can test the individual circuit's pins on the connector one at a time while a helper activates each function. Make sure the tester is grounded and apply the probe to one pin at a time as shown in the linked video.
I have also linked for you a photo that shows a 7-way socket and the common function assignments for each pin. The left turn signal should be carried on a yellow wire that connects to the pin at the 9-o-clock position.

If the light signal is present on the pin then the issue may be in your trailer's connector or its wiring.
Check the trailer plug's contacts for any sign of discoloration or corrosion. Even very slight greenish or whitish discoloration can indicate corrosion that can interfere with transmission of the lighting signals through to the trailer. If there is no signal on the truck connector then check that all the required relays and fuses are in place to activate the tow package.

expert reply by: Adam R

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