Trailer battery system
Smiley, I guess I have not spoken clearly. The trailer BRAKES are not connected to any electrical part of the system. The breakaway switch , on the trailer tongue, is connected to the battery system. The concept being, when the trailer is seperated from the tow truck suddenly, a pin is pulled from switch and trailer brakes are applied. The trailer brakes , in normal conditions, become powered ONLY by the tow vehicle electrical power.
The univolt is connected to the batteries. The batteries are connected to the fuses. No dc voltage can go into a univolt as there are diodes that are a one way electrical check valve, that prevent any dc voltage to enter unit. On most Airstreams, the blue wire in the trailer connector is the wire that conducts power to the trailer brakes. When the univolt is NOT connected to shore power, and the battery is NOT connected, the brakes will work properly.
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