Is There A Plug & Play Wire Harness That Bypasses The Factory Wiring In A 2014 GMC Sierra 1500
Updated 11/17/2025 | Published 12/26/2024
Products Featured in This Question
Question:
I am in need of a plug and play harness direct tk OEM specs on a 2014 GMC Sierra w/ tow package in place. My problem is w/ factory mounted plug ins on rear bumper both 7 round and 4 flat ,I want to replace wiring from this OEM plug in back to tail lamps as I am not getting signal to left turn nor running tail lights nor brakes either. Dont know exactly wherein problem lies but didnt want to chase it either.
asked by: Craig G
Expert Reply:
Hey Craig,
There isn't a plug and play wire harness to connect to your Sierra's tail light connectors so you would need to splice directly into the tail light wiring if you wanted to completely omit your factory wiring. Most likely just your 7-way connector has some bent, corroded, or dirty pins and needs to be swapped out. The factory replacement for your 7-way would be part # HM40975. I recommend giving the connectors a good glob of dielectric grease # 11755 to help protect them from corrosion.
Product Page this Question was Asked From
T-One Vehicle Wiring Harness with 7-Way Trailer Connector
- Custom Fit Vehicle Wiring
- Trailer Hitch Wiring
- Vehicle End Connector
- No Converter
- No Tow Package
- 7 Blade
- Plug and Lead
- Plug-In
- Visible
- Tekonsha
more information >
Featured Help Information
Instructions
Miscellaneous Media
Continue Researching
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Q&A: Recommended Hitch for a 2011 Chevy Express 4500 School Bus
- Q&A: Determining if 2019 Chevy Express Van has Tow Package for Installing Trailer Wiring
- Article: Wiring Trailer Lights with a 7-Way Plug (It's Easier Than You Think)
- Article: Trailer Wiring Diagrams
- Q&A: Air Force One Air Jumper Kit For Spartan K2 Chassis.
- Article: Installing an Electric Brake Controller on 2007-2013 GM Full-Size Truck or 2007-Present GM SUV
- Article: Brake Controller Installation: Starting from Scratch
- Q&A: Troubleshooting a Dexter Vault Hub that Has Popped Out Slightly
- Q&A: How To Determine If A Brake-Lite Relay Is Needed On My Flat Tow Setup
- Q&A: Is There a 7-Way That Plugs Into Black 12 Pin Plug Under Bumper on 2019 Chevy Express Van
- Q&A: Heavy Duty Hitch for 2021 4500 Chevrolet Express Cutaway
- Article: Flat Towing Package for 2006-2007 Chevrolet HHR
- Article: Which Hitches are Made in the USA
Kate F.
11/17/2025
Hey Craig, did swapping out the 7-way connector and adding the dielectric grease get your lights working again? Knowing how that fix turned out could really help others dealing with the same wiring issue on their Sierra.