Battery Disconnect Switch Wiring For a RV Trailer Breakaway Brake System

Published 04/20/2022

Question:

When you turn the quick disconnect switch to off from the trailer battery and you still have the 7 pin connector plug in is it suppose to have power going to the trailer?

asked by: Rudy

Expert Reply:

When a trailer manufacturer wires in a Disconnect Switch # SE29VR the disconnect will only break the 12 volt connection for lighting, fans and other 12 volt accessories inside the trailer. It will still have power on the 7-way connector since the battery also powers the breakaway brake switch and will also send power to smoke and CO2 detectors inside the RV. This ensures the battery is maintained while traveling of your vehicle battery so that there are no issues with the breakaway system should the trailer become disconnected in travel.

If the switch was added after the trailer was made it must still have the connection for the 7-way and breakaway switch when powered off.

expert reply by: Bud M