Troubleshooting 7-Way Trailer Connector on 1999 Ford F350 That Works Intermittently
Question:
What is the issue? Have 6 blade plug and connector. If wiggle plug sometimes lights work, sometimes not. Thinking of replacing connector and or plug. 1999 F350 SD Thanks!
asked by: Wanda H
Helpful Expert Reply:
Since the problem is intermittent, the most likely cause is corrosion on the blades in the connector on the vehicle or the sockets on the connector on the trailer. First, check those blades on the vehicle's connector for green or white corrosion. If the corrosion is minor, you can take a piece of sandpaper and remove the corrosion, but if its severe it's likely that the corrosion has spread to the interior of the plug and is interfering with the voltage coming through and the connector assembly should be replaced. We offer a replacement as part # 118243.
Next check the sockets on the connector on the trailer. Once again, if the sockets are corroded it'll be difficult to use sandpaper on them, if you have a file that's small and thin enough to fit in there, you can take a stab at cleaning them. If not, you'll need to replace the connector. We offer a trailer connector/junction box as part # HS381-9000 that would work great for you. The junction box provides a spot to neatly make your wiring connections so they'll be protected from the elements and easy to access if necessary.
When the blades and sockets have been cleaned or the connector/s have been replaced, it's a good idea to use some dielectric grease like # 11755 on the blades and in the sockets to prevent corrosion from occurring again.

Products Referenced in This Question
Dielectric Grease for Electrical Connectors, 2 oz.
- Accessories and Parts
- Trailer Wiring
- Wiring
- Dielectric Grease
- LubriMatic
more information >
Ford Replacement OEM Tow Package Wiring Harness, 7-Way (Super Duty)
- Custom Fit Vehicle Wiring
- Trailer Hitch Wiring
- Vehicle End Connector
- No Converter
- Factory Tow Package
- 7 Round - Blade
- Plug and Lead
- Plug-In
- Visible
- Tow Ready
more information >
Wiring Kit for Hydrastar Electric Over Hydraulic Actuators
- Accessories and Parts
- Brake Actuator
- Disc Brakes
- Hydraulic Drum Brakes
- Wiring
- Hydrastar
more information >
Product Page this Question was Asked From
T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
- Custom Fit Vehicle Wiring
- Trailer Hitch Wiring
- Vehicle End Connector
- Converter
- No Tow Package
- 4 Flat
- Plug and Lead
- Plug-In
- Visible
- Tekonsha
more information >
Featured Help Information
Instructions
Miscellaneous Media
Continue Researching
- Q&A: What is the Difference Between a 4-Way and 7-Way Trailer Connector
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Q&A: Will Curt Bumper Mount Trailer Hitch # E-3S Fit a 2007 Toyota Tacoma Bumper
- Article: Trailer Wiring Diagrams
- Article: Brake Controller Installation: Starting from Scratch
- Q&A: Installing a Brake Controller on a 2005 Toyota Tacoma Without Brake or 12 Volt Power Wire
- Q&A: Parts Needed to Install a 7 Way Connector on a 2021 Jeep Grand Cherokee without a Tow Package
- Q&A: How To Install 6/7-Way Trailer Connector On 2021 Jeep Grand Cherokee
- Q&A: Trailer Wiring Harness on a 2012 Toyota Tacoma
- Q&A: Trailer Hitch For 2024 Toyota RAV4 With Best Bumper Clearance & Ground Clearance
- Article: Trailer Hitch Installation Tips
- Article: Ram Trailer Tow Prep Package
- Article: How to Measure for Trailer Hitch Drop
- Article: Wiring Trailer Lights with a 7-Way Plug (It's Easier Than You Think)