The blue wire goes to the breakaway switch...can you clarify what the breakaway switch is and why the wire goes there?
asked by: Jeff P
A break away switch, like # HM20010, has a pin it that when pulled out completes a circuit from the battery mounted on the trailer to the trailer brakes. This allows the battery to apply voltage to the trailer brakes to stop the trailer should it become disconnected from the tow vehicle.
The charger, # 20011, receives 12 volt power from the tow vehicle on the black wire. It sends this power to the break away battery on the trailer to provide a maintenance charge along the red wire. The blue wire then goes out to the switch and the other wire on the switch to the trailer brake power wire.