Troubleshooting Brake Light Signals After Installation of ETBC7 Trailer Connector Kit
Question:
I installed the 7 way connector as part of the ETBC7 wiring kit a year ago and all seemed to be going well, but now it doesnt make contact for the brake lights. The installation went well in general, but this part of the result is disappointing. Is there a better socket for the car? I have replaced the trailer plug to make sure that wasnt the problem and verified the socket has brake light power. Occasionally when I make the connection everything works well, but most the time no lights.
asked by: Alan B
Helpful Expert Reply:
On an RV-style 7-way vehicle connector like the one included in our # ETBC7 kit you purchased (thank you) the brake light signals are carried on the same two wires as the turn signals. The contact pins for these right- and left-side functions are at the 3-o-clock and 9-o-clock positions, respectively. Please refer to the linked photo.
So, if your turn signals are working fine but your brake signals are not this tends to suggest the issue is on the vehicle side. It is easy to test the vehicle 7-way to find out if the brake light signals are reaching those contacts. Use a circuit tester like # PTW2993 while a helper applies the brakes in the tow vehicle. With the tester properly grounded you should detect a steady signal on the two pins when the brake pedal is pressed.
If not, then unplug the 4-pole harness from the 7-way and test the 4-pole's pins for the yellow and green wires, again while a helper activates the brakes. If you get brake signals here but not on the connected 7-way then you can replace the 7-way with # 37185. If you get no brake signals on the 4-pole then it may be damaged. Also you can check for any visible signs of corrosion - even slight greenish or whitish film - on the actual connector contacts and clean this away as needed. Since you do sometimes get proper signals this suggests either a ground or corrosion issue.
If not the easiest and most likely potential fix is to check the white ground wire on the vehicle's harness. This has to be firmly affixed to a clean bare metal spot on the vehicle frame in order for the harness to be able to pass the current required by all of the trailer lights. It can happen that a weak or marginal ground connection will allow passage of enough current for some light functions to work correctly but not all.
You can try sanding off any paint/primer/undercoat or cleaning away any grease/dirt/rust from that
grounding point to ensure good metal-to-metal contact. Dielectric grease like # 11755 can be applied to help prevent entry of moisture and dirt that can lead to corrosion problems in the future.
Products Referenced in This Question
Dielectric Grease for Electrical Connectors, 2 oz.
- Accessories and Parts
- Trailer Wiring
- Wiring
- Dielectric Grease
- LubriMatic
more information >
Adapter 4-Pole to 7-Pole and 4-Pole
- Trailer Wiring
- Wiring Adapters
- Multi-Function Adapter
- 4 Flat
- Plug and Lead
- 4 Flat
- 7 Round - Blade
- Hopkins
more information >
Product Page this Question was Asked From
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 >
Featured Help Information
Instructions
Miscellaneous Media
Continue Researching
- Shop: Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires
- Shop: 10 Gauge Primary Wire - Blue - per Foot
- Q&A: How to Bypass Factory Integrated Brake Controller on 2015 Chevy Silverado 2500
- Q&A: LG-1 Landing Gear Repair Kit Recommendation and Install Diagram
- Shop: Dexter Electric Trailer Brake Assembly - 12" - Left Hand - 6,000 lbs
- Shop: Dexter Electric Trailer Brake Assembly - 12" - Right Hand - 6,000 lbs
- Shop: Dexter BrakeRite SD Adapter for Ford/Chevy Integral Brake Controllers
- Q&A: Dexter EOH Disc Brake Actuator Response Time with GM Factory Brake Controller
- Shop: Trailer Wiring
- Q&A: What is the Difference Between a Class II and a Class III Hitch?
- Search Results: 44649
- Video: Choosing the Right Trailer Wiring
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Shop: Tekonsha Prodigy P3 Trailer Brake Controller - 1 to 4 Axles - Proportional
- Article: Trailer Wiring Diagrams
- Video: Choosing the Right Brake Controller
- Q&A: Brake Controller Installation on 2016 Mercedes-Benz Sprinter
- Search Results: 25580
- Shop: Trailer Hitch
- Shop: Tekonsha Prodigy P2 Trailer Brake Controller - 1 to 4 Axles - Proportional
- Shop: Brake Controller
- Q&A: Trailer Wiring Harness Recommendation for a 1999 Isuzu NPR
- Video: Review of etrailer - Brake Controller - ETBC7
- Search Results: 68149
- Shop: Fifth Wheel Hitch
- Article: Wiring Trailer Lights with a 7-Way Plug (It's Easier Than You Think)
- Search Results: equalizer
- Video: etrailer Trailer Brake Controller Universal Kit Review
- Q&A: Replacement Connector for a Pollak PA66-MD40
- Article: Brake Controller Installation: Starting from Scratch