Do Circuit Breakers Provided with ETBC7 Have Diodes to Prevent Car Battery Discharge

Question:

Im wondering if the circuit breakers included prevent back flow. Specifically curious about the 40 amp breaker as it forms a direct connection between the car battery and the trailer when the trailer is hooked up to the car. If I didnt detach the trailer from my car, then left a high energy consuming appliance running on the 12V supply, then by morning both batteries would be dead unless the circuit breaker prevents this somehow.

asked by: Zach

Expert Reply:

The breakers included with the # ETBC7 Brake Controller Installation Kit don't have diodes. If you're worried about unintentional power draw on that 12V trailer accessory feed discharging the vehicle battery, you can install an isolator solenoid like # PK5231201 which will shut down that feed when the vehicle ignition is turned off. The solenoid would install inline on the 12V circuit from the battery, with the center terminal ran to a ignition switched circuit.

expert reply by: Mike L