Trailer Wiring Harness Blows Fuses and Turns On Reverse Lights on a 2002 Nissan Pathfinder

Updated 02/26/2014 | Published 02/25/2014

Products Featured in This Question

Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

(26)

$45.91

LCD Digital Circuit Tester

(28)

$28.06

Question:

I have a 2002 Nissan Pathfinder and purchased the T-One Vehicle Wiring Harness 118361 about a year ago and installed it but am now having issues with the converter box blowing fuses on my tail light circuit and intermittantly turning on my reverse lights. I am looking to purchase a better Vehicle Wiring Harness and was considering the one made by Curt C55361. C55361 does not say anything about LED lights but similar part C56175 says Not recommended for Nissan Pathfinders with LED lights. I have two main questions: 1 Will C55361 work with LED lights? 2 Why is C56175 not recommended for Nissan Pathfinders with LED lights? My Pathfinder has LED bulbs for everything in the back and my trailers also have LED lights.

asked by: Jeff

Helpful Expert Reply:

I do not recommend Curt powered trailer wiring harnesses for LED taillights because some of the battery power bleeds through and can dimly light up LED bulbs. Harness # C55361 should not have that issue since it does not have a direct connection to the vehicle battery.

The harness you are using now, # 118361, might not be the problem and it is possible that if the harness is not the problem that when you install a new one the same thing will happen. It almost sounds like there is a bent or broken pin where the harness tees into the vehicle wiring so you will want to check that. There is no other way that it could turn on the reverse lights unless the connections were also very corroded.

To test the converter, you will need a circuit tester such as # PTW2992 and disconnect the trailer from the vehicle. You will need to test the wires going into the converter from the vehicle while someone runs through the lighting functions. If the functions are not correct going into the box, then the issue is something in the vehicle wiring.

If the signals are correct going into the box, then test the wires on the output side of the box. If they are not right coming out of the box, then the converter is bad, and you will need to replace the harness. If the signals are correct going in and coming out, then the issue is with the trailer.

Make sure that both the vehicle side and trailer side connectors are clean and free of corrosion. On the trailer side make sure the main trailer connector ground and all of the light grounds are attached to clean and corrosion free bare surfaces. Then inspect the wiring from the connector to the lights. Look for any breaks in the wires with copper strands touching bare metal. This can cause shorts and the exact issue you are describing.

I have included some links that should help you.