Installing 7-Way and 4-Way Connectors on a 2015 GMC Acadia

Published 06/07/2018

Products Featured in This Question

7- and 4-Pole Trailer Connector Socket w/ Mounting Bracket - Vehicle End

(2582)

$36.50

T-One Vehicle Wiring Harness for Factory Tow Package - 7-Way Trailer Connector

(182)

$59.57

No-Drill Mount for Electrical Mounting Bracket - Short

(1153)

$26.16

Question:

I have a wiring harness pre installed. And ordered a HM40975. Jon G suggested part 118271 to connect the 2. My question is, will part #118271 run the 7 pole and the 4 flat on part HM40975? Or just the 7 pole? Thank you.

asked by: Nathan S

Helpful Expert Reply:

The Hopkins # HM40975 that you referenced plugs into a US Car Connector (see attached picture). This typically will replace a factory 7-Way on a vehicle so if your 2015 GMC Acadia didn't come with a 7-Way you might not have that connector. If it does exist though it will be located somewhere around the trailer hitch.

If you don't have the US Car Connector but you would like fully functioning 7-Way and 4-Way connectors then we do have a solution for you. Simpy install the T-One Vehicle Wiring Harness # 118271 (if you have the factory tow package) and then swap out the included connector with the Hopkins # HM40975 that you referenced. To keep from drilling into your vehicle or trailer hitch use the No-Drill Mount Bracket # 18140 as well.

Attached are some installation videos for you to check out.

expert reply by: Jon G

click to enlarge

Nathan S.

6/7/2018

Jon G.

6/7/2018

Yes it will. The 4-Way just carries basic lighting functions for your trailer. The 7-Way includes the basic lighting functions as well as the reverse lights, 12V power, and brake controller output. The # HM40975 basically splits those basic lighting functions so that they will be sent to both the 4-Way and the 7-Way connector on this unit.