Troubleshooting 2016 Nissan Frontier Trailer Wiring with No Turn Signals

Published 11/01/2018

Products Featured in This Question

Replacement Wiring Harness for Tow Ready Nissan Vehicle Wiring Harness

(81)

$20.52

Hopkins Plug-In Simple Wiring Harness for Factory Tow Package - 4-Pole Flat Trailer Connector

(173)

$20.03

LCD Digital Circuit Tester

(26)

$26.67

Question:

I have had my 2016 Nissan Frontier Desert Runner since October of 2015 without any wiring problems at all. I noticed that my left blinker on my trailer didnt work and within a week, the right one wouldnt work. Hooked trailer to another vehicle and everything works fine. I have the 4-5ft harness on my truck that plugs directly into the wiring on the back of my truck. With a test light, I checked the pigtail and did not have power to the blinkers, I unplugged it from the trucks wiring and checked it where it plugs into there. Again, I have power to the running lights, but no power to either blinker. Both blinkers on the truck itself work just fine. Do you have any suggestions on what I should do next?

asked by: Pat W

Expert Reply:

Thank you for describing the trailer lighting issue you're having and the testing/troubleshooting steps you've taken to diagnose the cause.

If I understand correctly you have a 4-pole harness such as # HM43575 which does indeed plug in to the OEM tow package wiring under the vehicle. For reference I linked a photo of this item's OEM plug which should match what is on the Frontier. Since you have tested the contacts on the vehicle plug where this item connects (with a tester like # PTW2992) and have again found no signals there this tends to suggest the problem could be a bad fuse or relay in the Frontier's power distribution boxes or damage to its wiring further upstream of the point where you tested.

I checked an online version of the 2016 Frontier's owner's manual but it does not include specifics about the location of the trailer turn signal fuses; but as if often the case, the lids on the fuse boxes will have a legend telling you the fuse location and value for each fused circuit.

The 2016 Frontier has three fuse boxes; two are in the engine compartment on the passenger side near the firewall (please see the engine compartment diagram taken from the manual) and one is in the passenger compartment, on the dash to the right of the open glove box cover.

Check the lids for a legend that tells you which fuses are related to trailer lighting. Often turn signals will be fused separately for each side of the trailer.

Once you have replaced your fuses/relays you might want to take some time to inspect all of the wiring on the trailer to find the fault that caused the fuses to blow. It could be something as simple as worn insulation or a wire rubbing on the trailer frame that caused the short.