Troubleshooting Trailer Brake Lights and Turn Signals Not Working After Installing 7 Way on Vehicle
Question:
I recently made a purchase for a 7 was plug/harness for my GMC Acadia as well as the hitch and everything to go with it it all mounted up nicely plugged the harness in and hook up my camper and the running lights all work but not my brake or turn signals???
asked by: Gary L
Expert Reply:
If you've just installed a 7 way connector like the # ETBC7, you'll want to start by testing the plug on the vehicle using a circuit tester like the # PTW2979 to make sure that each pin is operating properly; you can refer to the photo attached or a helpful article that I've linked for information on testing the circuits. I would also recommend making sure that your ground wire on this harness is firmly grounded to a paint and rust free spot, as ground wires are the most common cause for faults like this since. The harness can supply power to the running lights since they require a small amount of amps, but adding the other lights into the mix creates complications that can pop up when the harness isn't properly grounded.
If all of the circuits on the harness are properly functioning when you test them, this issue is going to be on the trailer, so you'll want to trace the wires on that circuit back to make sure they are not damaged in any way; you'll want to replace any cut or damaged wiring as needed with something like the # 10-1-1 (sold by the foot) and heat shrink butt connectors # DW05745-10.
If you can confirm that the wiring on the trailer is in good shape and all of the circuits on the 7 way connector are working, but the lights still are not, please let me know and I can give you a few other things to look at.
Products Referenced in This Question
Deka Heat Shrink Butt Connector - 12-10 Gauge - Nylon Insulation - Yellow - Qty 10
- Wiring
- Wire Connectors
- Butt Connectors
- 12-10 Gauge
- Deka
more information >
Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires
- Accessories and Parts
- Trailer Brake Controller
- Installation Kits
- etrailer
more information >
Product Page this Question was Asked From
Featured Help Information
Instructions
Miscellaneous Media
Continue Researching
- Shop: Trailer Wiring
- Q&A: Troubleshooting No Trailer Turn/Brake Signals with 2007 GMC Acadia
- Article: Trailer Wiring Diagrams
- Q&A: Working Running Lights, But No Turn Signals or Brake Lights On Trailer
- Q&A: Trailer Running Lights Do Not Work but Brake Lights and Turn Signals Do Work
- Q&A: Trailer Wiring Has 5-Wires White, Yellow, Green, Yellow/Brown, and Green/Brown
- Q&A: Trailer Brake Lights Work But Turn Signals Do Not Work
- Shop: Pollak 5th Wheel / Gooseneck T-Connector with 7-Pole - Ford, GM, Dodge, Nissan w/ Factory Plug
- Shop: Tow Ready Replacement 7-Way Harness and Socket for Factory Tow Package
- Q&A: What is the Difference Between a Class II and a Class III Hitch?
- Shop: Trailer Hitch
- Shop: 7- and 4-Pole Trailer Connector Socket w/ Mounting Bracket - Vehicle End
- Search Results: trailer hitch wiring
- Video: Choosing the Right Trailer Wiring
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Shop: Brake Controller
- Video: Tow Ready 4-Pole Mounting Bracket Installation
- Search Results: trailer hitch
- Q&A: What is the Difference Between a 4-Way and 7-Way Trailer Connector
- Shop: Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires
- Video: Choosing the Right Brake Controller
- Shop: Curt Powered Tail Light Converter with 4-Pole Flat Trailer Connector
- Article: Wiring Trailer Lights with a 7-Way Plug (It's Easier Than You Think)
- Search Results: brake controller
- Shop: Gooseneck Hitch
- Search Results: hitch
- Article: How to Choose the Right Trailer Hitch Class
- Video: Curt Powered Tail Light Converter Installation - 2023 Kia Telluride
- Shop: Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
- Article: My Trailer Hitch Doesn't Fit