Troubleshooting 7-Way Trailer Connector on 1999 Ford F350 That Works Intermittently  

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 # e99011 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.

I've linked to installation videos for the parts mentioned above.

expert reply by: Mike L

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