Barkoff - I agree with whomever said that a good working 12v system with clean/tight connections to refrig should power that 3rd way just fine while driving. I like to get away from the propane as much as possible and rarely hook up to 120v AC. Installed an aux RV batt for that refrig 12v power (the whole camper actually) and my alt charges both batts just fine when I select that 2 batt charging option. It should work.
