Electric Brakes Lock When Connected to Vehicle And Breakaway Battery Is Powered

Updated 02/03/2010 | Published 02/02/2010

Products Featured in This Question

Hook Probe Circuit Tester

(60)

$12.27

Adapter 7-Pole to 6-Pole Universal with LED Tester

(5)

$17.85

Question:

i have a six wire male on a trailer with electric brakes and a 7 way female on my pickup truck..trailer brakes are locked when plugged in..light on brakwe controller on dash is out when plugged in but when i de-powrr the breakaway battery everything is ok..could problem be the breakaway connector

asked by: clarence

Expert Reply:

It sounds to me as if you have the breakaway wired incorrectly. When the switch is installed in the breakaway there should be no power going out on the brake feed circuit (blue wire).

The breakaway should be wired as follows. White wire should be ground. Black wire should go from the 6-Way trailer connector to the breakaway battery positive terminal to charge the battery. Blue wire leaving the breakaway battery should go to the breakaway switch. The blue wire leaving the breakaway switch should go to the electric brake feed wire to the trailer brakes (usually blue).

Another possibility is that the 7-Way to 6-Way connector is improperly wired. If your connector can be rewired you should use a circuit tester, item # PTW2993, and test the connections and rewire the connector by function if it is improperly wired. If you cannot rewire your adapter, we have one that can be wired properly. The Adapter 7 Pole to 6 Pole Universal with LED Tester, item # 47525, can be wired to switch the brake and power wire connections to match your trailer.

expert reply by: Robert G