Trailer Brake Controller Only Works with Pin Pulled on Trailer Breakaway Kit

Updated 12/11/2012 | Published 12/10/2012

Products Featured in This Question

Trailer Breakaway Kit Battery Charger for 12V, 5-Amp Battery

(50)

$7.87

Hopkins Engager Trailer Breakaway Kit w/ Charger, LED Tester, and 5 Ah Battery - Side Load

(746)

$60.86

Cordless Circuit Tester

(15)

$19.26

Question:

I have a 2002 Chevrolet 3500 dually with the Draw Tite activator 2 break controller that I just installed with the plug and play pigtail. The only way the brakes work on my 40Ft Big Tex tandem dually axel trailer is when the breakaway pin is removed. Then the brakes function properly. When I re the pin I get an error that tells me the brakes are not wired correctly. With the trailer disconnected the brakes lock with the pin removed. My question is – Is there a way of testing the charger? I think there is a short in it somewhere but I just don’t want to parts change. I want to make sure that is the problem first.

asked by: Greg C

Expert Reply:

This does sound like a short or a ground issue. It could also be corrosion inside or on the trailer connectors. You can test the charger by applying 12 volts of power to the power wire on the charger and then testing the output side to the breakaway battery on the trailer using a circuit tester like # PTW2979 to see if it is applying power to the system.

Make sure that all ground from the main trailer connector, to the breakaway system, and on to the brake magnets are all grounded to clean and corrosion free bare metal surfaces. If not, that could be the problem. Also check all power wires related to the brakes and breakaway systems for any nicks with exposed wires that may be touching bare metal.

You also need to make sure that everything is wired up correctly. From the back of the trailer connector, the power wire will need to go to the positive battery terminal on the breakaway battery. The ground wire will need to go to the negative battery terminal and to the trailer frame.

The brake output wire will need to go into the breakaway switch from the 7-Way. The other wire from the breakaway switch connects to the positive battery terminal. I have included a picture that should help from the instructions for the Hopkins Engager breakaway system, # 20099.

I have also included some links on installing and testing breakaway systems.

expert reply by: Michael H