12V is needed to power the control board. Depending on what you set it to (auto/LP) will determine what it uses to cool.
Auto: it will always choose 110VAC if it's available, if not AND the propane is turned on it will light the flame and run on LP. When you plug the trailer back in to shore power, the control board will shut off the flow of propane and send 110V to the heating element.
LP mode- it will only operate on LP.
EITHER WAY requires 12V to the control board, most will continue to operate until voltage drops to about 11.4 volts (I think that's the threshold).
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2012 Copper Canyon 273FWRET being towed by a 1994 Ford F350 CC,LB,Dually diesel.
Airlift 5000 bags, Prodigy brake control, 5 gauges on the pillar.Used to tow a '97 Jayco 323RKS.
Now an RVIA registered tech. Retired from Law enforcement in 2008 after 25+ yrs.
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