If There Is Tow Package Port On 2018 GMC Terrain Can You Use Trailer Wiring for Factory Tow Package

Question:

I have located a plug under the driver side bumper that had a dummy plug on it. Im reading this means I can just plug the wiring harness into it. But inside my fuse panel K2 and K3 are empty. Do I need the wiring harness that plugs into both tail lights or the wiring harness that plugs into the existing plug under the bumper? Thank you for your assistance

asked by: James C

Expert Reply:

In regards to a 2018 GMC Terrain, not all models with the tow package port will actually have the tow package wiring. In other words, the port may be present but the wires are not run from this to the fuse block therefore the port is inoperable even with the relays handy. The best way to tell is by calling the dealer but if there are actual contacts/terminals in the relay locations assume they are not already installed then you can use the factory tow package port on the rear. The Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
Item # C94FR is for models with the tow package and the Tekonsha Circuit Protected Vehicle Wiring Harness with Installation Kit # 119250KIT is for models without the towing package.

expert reply by: Conner L