Troubleshooting Trailer Light Functions Connected to Curt Trailer Harness on 2015 Nissan Pathfinder

Updated 04/16/2020 | Published 04/15/2020

Products Featured in This Question

Curt T-Connector Vehicle Wiring Harness for Factory Tow Package - 7-Way Trailer Connector

(57)

$88.41

LCD Digital Circuit Tester

(28)

$27.83

Question:

I did the install as the video shows, all relays are installed, under the hood had them from the factory. My trailer has no lights at all, no turn signals, brakes or running lights. My battery was also drained after doing this.

asked by: Austin C

Expert Reply:

The Curt T-Connector Vehicle Wiring Harness for Factory Tow Package - 7-Way Trailer Connector # C56357 sounds like it was installed correctly and wouldn't have any draw on your battery except when a trailer is connected.

I recommend using a circuit tester like # PTW2992 to test each function when the trailer is not connected to confirm you did the installation correctly and all relays and fuses are working correctly. If not, check the connections again and then check fuses. Relays are not easy to check and often just need replaced if all other functions are correct. If you left the doors open without disconnecting the battery, then often a battery gets drained from the installation and will need recharged which would cause that issue with the trailer.

If your vehicle side is working properly then the issue on the trailer side sounds like a bad ground on your trailer. If the main ground is bad it would drain your battery and would not allow the lights to work properly. The ground needs to be bare metal to metal and free of any corrosion, rust, or debris. Another common issue is corrosion between connectors which a little sand paper on the pins can clean up.

expert reply by: Jason S