Brake Controller Reading No Connection When Towing Trailer
Question:
Our controller in our truck just started indicating that our trailer brakes are disconnected. We replaced the seven pin on the trailer and had truck plug tested and it is still I dictating a disconnect. Any answers on why? Should we replace controller?
asked by: Mickey G
Helpful Expert Reply:
Since you've replaced the connector on the trailer and the connector on the vehicle checked out okay (no corrosion in it?), the next most likely culprit would be the brake magnets. Each magnet will have two wires exiting it, one should be securely grounded to the trailer frame. The other should connect to the brake wire that delivers voltage from the brake controller. If either of the brake magnet grounds are loose, or the point where they ground to the trailer frame is corroded or dirty, it could prevent a bad electrical connection.
Another possibility is a worn brake magnet. If the faces of the brake magnets that ride against the inside armature surface of the brake drum are worn to the point where the copper wire that's inside them is exposed and making contact with the brake drum, it could explain why the controller isn't 'reading' your trailer.
A third possibility would be a loose or broken connection in the brake wire somewhere on the trailer. Trace the brake wire back from the trailer connector back to the brake assemblies, making sure all connections are tight and aren't exposed to the weather.
I've linked you to our trailer brake controller troubleshooting help article, I hope you find it helpful.
