Troubleshooting Trailer Running Lights Not Working with 2018 Nissan Frontier
Updated 01/19/2026 | Published 07/23/2019 >
Question:
I need a blue relay. the installation video calls for tow harness to be hooked up at passenger side kick panel, then 3 relays to plug to nearness, other instructions mentioned relay plugs under steering column? My issue is: trailer running lights dont work, brake/signals do.
asked by: Juan M
Expert Reply:
On certain Nissan vehicles like yours a 4th blue relay is sometimes needed to activate the trailer running lights circuit. This appears to be the case with your 2018 Nissan Frontier.
The blue relay that you need is included in the Curt Relay Kit # C57000 and the harness you need to access to plug the relay in is indeed located in the cab behind the dash to the left of the steering column. I have attached an image that might help.
Product Page this Question was Asked From
Curt Relay Kit for Nissan Armada or Titan Aftermarket Tow Package
- Accessories and Parts
- Trailer Wiring
- Relays
- CURT
more information >
Featured Help Information
Instructions
Miscellaneous Media
Continue Researching
- Shop: Trailer Wiring
- Shop: Curt Relay Kit for Nissan Armada or Titan Aftermarket Tow Package
- Shop: Brake Controller
- Shop: Trailer Hitch
- Q&A: Troubleshooting No Trailer Running Lights with 2018 Nissan Frontier
- Shop: etrailer Trailer Hitch Receiver - Custom Fit - Matte Black Finish - Class III - 2"
- Shop: Towing Mirrors
- Video: Comprehensive Review: Curt Relay Kit for Nissan Armada or Titan Aftermarket Tow Package
- Search Results: weight distribution hitch
- Shop: Fastway e2 Weight Distribution w/ Sway Control - Round - 6,000 lbs GTW, 600 lbs TW
- Video: All About the Blue Ox TrackPro Weight Distribution w/ Sway Control
- Article: 5 Things to Know About Weight Distribution Hitches
- Shop: Blue Ox TrackPro Weight Distribution w/ Sway Control - 7-Hole Shank - 6K GTW, 600 lbs TW
- Q&A: Troubleshooting Trailer Running Light Circuit of 2018 Nissan Frontier Not Active
- Q&A: Solution for Trailer Running Light Circuit Not Active on 2019 Nissan Frontier
- Q&A: My Nissan Frontier Already Has 3 Relays And Running Lights Still Do Not Work
- Q&A: Trailer Running Lights Not Working on 2012 Nissan Xterra
- Q&A: 2022 Nissan Frontier SV - Troubleshooting No Running Lights On Trailer
- Q&A: Troubleshooting Trailer Running Light Circuit Not Functioning on Nissan Frontier
- Article: Brake Controller Installation: Starting from Scratch
- Article: Trailer Hitch Balls
- Article: Top Weight Distribution Hitches for a Buttery Smooth Ride
- Article: Trailer Wiring Diagrams
- Article: Wiring Trailer Lights with a 4-Way Plug (It's Easier Than You Think)
- Article: Trailer Tire Sizing




Cito
1/19/2026
From looking at the picture, and seeing other posts, don't you mean RIGHT by passenger seat near glove box? Just curious as this has become a witch hunt and I am excited to see this post.