Troubleshooting Electric Brakes Locked Up With Breakaway Battery Disconnected

Updated 07/29/2019 | Published 07/27/2019

Question:

On a goose neck trailer can a breakaway battery on a 6 way plug short out? The trailer brakes are held tight, makes no difference if I unplug the breakaway battery or not? The brakes are still tight, with a bulb tester ii shows the battery is fine. What is the problem?

asked by: Tom

Expert Reply:

The battery in a standard breakaway kit like the Hopkins Engager Push-To-Test Trailer Breakaway Kit # 20099 is designed to lock up the trailer brakes for 15 minutes once the pin is pulled. The only way that the battery would still be able to power your trailer brakes when you disconnect it is if you disconnected it from the end that it receives power and not from the end that would be sending the power to your brakes.

It is definitely possible for the battery to get messed up but if you have truly disconnected your breakaway battery then the only other way that your brakes would still be locked up is if they are somehow receiving power from your 12V pin. This could meant that your auxiliary battery is sending that power or your 6-Way connector has shorted out/become damaged and is connecting the 12V power to your brakes. Another possible solution is that your vehicle side connector is configured opposite your trailer connector so the 12V power pin from your vehicle is connected to the brake circuit on your trailer (this is one of the most common reasons).

Make sure the functions for your tow vehicle and trailer match up (see attached photo) and then look for any places where you have broken or damaged wires on both your 12V and brake circuits as well as check both your tow vehicle and trailer connectors for anything that could be causing issues.

expert reply by: Jon G