Do I have a 2-way fridge?

[Tiffany]

We have a 1989 Starcraft Galaxy with a Dometic RM 2190 fridge.  It seems to work only on propane or DC electric, but not AC.  There is no switch to select AC and I've tried to run it through the converter when plugged in to shore power and the fridge set to DC but it doesn't work that way.  On propane it works fine(ish), and that's good enough for me but I'd like to use house power to precool the fridge the night before a trip.  The Galaxy lives in the garage and I'm not willing to light the propane while it's in there.

I've only seen references to 3-ways on these boards, but is there such thing as a 2-way?*  It is after all a 20 year old camper, so is this just old technology?  Is is possible to convert to a 3-way so I can use AC power from the house?  Since the converter takes 120VAC and makes 12VDC I think the fridge should work like that.  Thanks!

*I just reread that sentence and giggled

[wavery]

We have a 1989 Starcraft Galaxy with a Dometic RM 2190 fridge.  It seems to work only on propane or DC electric, but not AC.  There is no switch to select AC and I've tried to run it through the converter when plugged in to shore power and the fridge set to DC but it doesn't work that way.  On propane it works fine(ish), and that's good enough for me but I'd like to use house power to precool the fridge the night before a trip.  The Galaxy lives in the garage and I'm not willing to light the propane while it's in there.

I've only seen references to 3-ways on these boards, but is there such thing as a 2-way?*  It is after all a 20 year old camper, so is this just old technology?  Is is possible to convert to a 3-way so I can use AC power from the house?  Since the converter takes 120VAC and makes 12VDC I think the fridge should work like that.  Thanks!

*I just reread that sentence and giggled

You are quite right. The fridge should work ~OK when running on 12V from the converter. However, it will take about 24-hours to cool down adequately. Even then, it should keep cold items cold but it may not cool down room temperature items very well.

[coach]

Looks like a 2-way fridge to me
diagnostic manual RM 2190

There are plenty of 12v fridges that are not wired to the converter.
Older converters didn't charge batteries, they don't put out enough current to power a fridge. You'd need to check you wiring.

You could use a battery charger to power the fridge either via a battery or directly, newer small fridges are rated ~ 120 watts, that's 10 amp or so @ 12vdc.

"The 12 volt heating element is rated at 95 watts and has
a current consumption of 8 amps; therefore, the refrigerator
should not be left operating on 12 volt when the
engine in NOT running and charging the battery."

[92_Flagstaff]

Here's a link to an owner's manual for this Dometic model, which also confirms it is a 2-way model.

Dometic RM 2190 - Owners Manual

[austinado16]

Same fridge as in my '87 Nova.  It's not hooked into the converter, so it's 12v function is only off the camper battery, or the tow vehicle.  It's only to be used when towing to and from the campground.

So fire the fridge up on propane the day before, freeze your meets in your house refrigerator, and then prior to heading out, stock the camper fridge with cold food, and the frozen meets, switch it to 12v and head out.

Remember, the fridge must be level during operation, otherwise the amonia inside will puddle and create crystals that will block the small orifaces in the refrigeration pipes.  This effectively kills the fridge and ruins it permanently.  So even during pre-cooling, level the camper.  This rule doesn't apply to towing and having the fridge on, because the camper is bouncing around  and that keeps the amonia moving.