Camping without power, our 3 way works just fine on
propane, but it blows out while moving. We start out with a cold, full
refrigerator. It will stay that way for at least two hours, turned off. If you'll be traveling longer, turn it on after your rest stop and off again at the next one. Don't leave it running with the engine off. It's worked for us for the past 11 years.
Lynn and Pam