Trailer Running Lights Are Brighter Than Brake Lights When Vehicle Lights Are On
Question:
I have a 2014 Mercedes Benz Sprinter van with an aftermarket wiring harness. The harness seems to be working properly except for the running lights on the trailer. When the lights of the van are on, the running lights on the trailer are at full brightness and not dimmed as they should be when no brakes are being applied. Ive done some research on etrailer and I believe that Item number C35FR could solve this problem? My trailer uses a 4 flat connection and my van has a 7-way plug. Will this item work fine even though it has 5-way connection? I assume it will work base on the description 7-way to 4-way/5-way trailer adaptor. Thanks for the help!
asked by: Mike F
Expert Reply:
The 7-Way to 5-Way/4-Way Trailer Adapter # C35FR is the correct adapter for connecting your 4-way trailer connector to the 7-way connector on you 2014 Mercedes-Benz Sprinter as long as your trailer has LED Lights. Usually how you know you need the adapter to run your trailer with LED lights is because of a light out warning on your vehicle that keeps your lights from working correctly.
From the description of the problem you are having, it sounds like there is an issue with the running lights only. checking the grounds for your trailer since most ground issues surface when multiple functions of your trailer happen at once. Keep in mind that some lights ground through the mounting hardware so make sure they are mounted securely to clean metal. Next check the connectors on you aftermarket harness to ensure that all of the connections are secure and connected correctly.
I included an article that goes over some wiring troubleshooting for you to take a look at.
Product Page this Question was Asked From
7-Way to 4-Way/5-Way Trailer Adapter for Vehicles with Lamp-Out Sensors Towing Trailers with LEDs
- Trailer Wiring
- Wiring Adapters
- Multi-Function Adapter
- 7 Round - Blade
- Plug Only
- 5 Flat
- 4 Flat
- CURT
more information >
Featured Help Information
Miscellaneous Media
Continue Researching
- Video: Curt 7-Way to 4-Way/5-Way Trailer Adapter Review
- Video: Review of Curt Wiring - Wiring Adapters - C35FR
- Video: Pollak Wiring - Wiring Adapters - PK12716 Review
- Video: Pollak 7 Pole to 4 Way Connector Adapter Installation
- Q&A: RV Kitchen Faucets with a 1-1/4" Diameter 1-Hole Installation
- Shop: Pollak Black Plastic, 7-Pole, RV Blade-Style Trailer Socket - Vehicle End
- Shop: 7-Way to 4-Way/5-Way Trailer Adapter for Vehicles with Lamp-Out Sensors Towing Trailers with LEDs
- Shop: Pollak Black Plastic, 7-Pole, RV-Style Trailer Connector - Trailer End
- Shop: Pollak 7 Pole to 4 Way Connector Adapter
- Shop: 7-Way Round RV Style Trailer Connector - Trailer Side
- Shop: Pollak Replacement 7-Pole, RV-Style Trailer Connector Socket - Vehicle End
- Shop: Replacement Crossbar for Thule Xsporter Truck Bed Ladder Rack - Qty. 1
- Shop: Tailgate
- Shop: Truck Bed Tailgate Assist
- Q&A: Troubleshooting Trailer Tail Lights That Do Not Work When Other Lights Do Work
- Q&A: 7-Way to 4-Way Adapter for a 2017 Volkswagen Tiguan
- Q&A: Trailer and Tow Vehicle Brake Lights Not Working when 7-Pin Trailer is Connected to 4-Pin Vehicle
- Q&A: Is Curt 7-Way to 4-Way/5-Way Trailer Adapter Also Compatible With Incandescent Lights
- Q&A: Troubleshooting Bulb Out Sensor After Using Bulb Out Adapter C35FR
- Q&A: What is the Correct Replacement for a PA66-MD40 on a 2011 Mercedes Benz GL Class?
- Shop: Trailer Hitch
- Article: Trailer Wiring Diagrams
- Video: Choosing the Right Trailer Wiring
- Search Results: 44649
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Shop: Trailer Wiring
- Search Results: 25580
- Video: Choosing the Right Brake Controller
- Shop: Brake Controller
- Article: How to Choose the Right Trailer Hitch Class
on Trailer Wiring
