After Replacing Trailer Side Connector the Trailer Brakes Stopped Working

Question:

I own a 2007 keystone travel trailer. I just replaced the cable that runs from the trailer to the tow vehicle and now my brakes dont work. i checked the connections and they are all solid. Any ideas?

asked by: John

Expert Reply:

It is possible that in the process of installing the new trailer side connector that a ground connection got knocked loose or something may not be wired correctly. This is common because if you try to install a new connector color for color on the old harness, they may not match up. You have to go by function.

On a 7-Way, the brake output pin if looking at the back of the connector where the wires attach, is located in the 5:00 position. That is the power wire for the brake magnets. Make sure the ground wires for the brake magnets and the main trailer connector ground are all attached to clean and corrosion free bare metal surfaces.

If you have a different style connector you can use the diagrams in the FAQ I have linked. Again, go by function, not color.

If everything is wired up correctly use a circuit tester like # PTW2993 that you referenced to test the truck side connector without the trailer attached. Have someone apply the manual override on the brake controller while you test the trailer connector. If the signal is not getting back to the vehicle side connector, then the issue is on it, not the trailer. I have linked our brake controller troubleshooting FAQ for you.

expert reply by: Michael H