Troubleshooting Engager Trailer Breakaway System That Keeps Brakes Engaged

Question:

My breakaway switch had been pulled for a long time I bought another breakaway plug wired it in was checking breaks today I pull the plug I hear the breaks engage I put the plunger back in as long as. I Have the battery in the box breaks are engaged if I pull battery out they release the two wires coming out of the plunger are they polarity sensitive

asked by: Rob L

Expert Reply:

It sounds like you have a short in your Engager breakaway kit's wiring that is allowing the breakaway battery's power to reach your brakes even when it should not. With the plunger in place there should be no power going to the brakes. There is likely to be some wiring that is shorted to the trailer frame that is letting the battery power bypass the switch and reach the brakes.

You will need to inspect and either repair or replace any damaged wiring. Look for wires with worn or cracked insulation, especially at points where it may contact the trailer frame or other parts of the trailer.

The switch's blue and black wires need to be connected as shown in the linked wiring diagram.

expert reply by: Adam R