Troubleshooting No Running Lights on Trailer When Hitched to 2005 Nissan Frontier with 4-Pole

Question:

My 2005 Frontier has an aftermarket tow package. The a/m harness converts from factory square connector to flat four wire pin for trailer connection. Verified all trailer lights work by connecting with another vehicle. When connected to my Frontier, signals and brake lights all work, but no running lights. Problem is the same with my other two trailers so it must be the truck. Seems there is no power in brown wire at the square end of the factory harness. Thanks for your suggestions.

asked by: Allan

Expert Reply:

I suggest you check that the Frontier has the required relays installed. Please refer to the linked video at the 1:50 mark; this shows a 2005 Armada. If you are missing your relays you can use part # C57000 that is required to complete the circuits for your Nissan's non-factory-installed tow package.

expert reply by: Adam R