4-Way Trailer Wiring Harness For 2015 GMC Sierra 1500 Base

Updated 03/17/2022 | Published 03/16/2022

Products Featured in This Question

Dielectric Grease for Electrical Connectors, 2 oz.

(1481)

$10.94

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

(465)

$31.70

Tekonsha Tail Light Converter with 4-Way Flat Trailer Connector and Install Kit

(380)

$43.77

etrailer Trailer Hitch Receiver - Custom Fit - Matte Black Finish - Class IV - 2"

(293)

$246.94

Question:

I have a 2015 GMC Sierra 1500 base model. It did not come with the trailer hitch assembly. Do you know what I need to be able to power lights on the trailer? This will most likely be used with a Uhaul trailer if that helps.

asked by: Brian G

Helpful Expert Reply:

Yes, to power trailer lights with your 2015 GMC Sierra 1500 you will need a 4-way flat trailer connector, and your Sierra should have a round plug under the truck and behind the bumper like you see in the accompanying photo (though it won't be hanging down exactly like that). Assuming you do have that plug, you can use a simple plug-in connector, which is the following part number:

- T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # 118384

And to prevent corrosion on the 4-way it is highly recommended you use Dielectric Grease for Electrical Connectors # 11755.

It would be very surprising if that round connector isn't there, but if not, you will need to hardwire a connector, the Tail Light Converter Hardwire Kit # 119178KIT.

Since you also mentioned not having a trailer hitch receiver, for just pulling a U-Haul trailer you'll want the best value and easiest install which you can just bolt on, which for your 2015 GMC Sierra 1500 is the etrailer Trailer Hitch Receiver # e98860.