My fridge works on AC and LPG but not on 12v.. I checked to see if it was getting power and it is. My suspicion is the control board, but I was hoping someone might be able offer the benefit of their experience.

Mine is only designed to work on LP or AC. I know of none that work on DC.

First, are you positive that you have a 3 way fridge?

87bob, you might want to share what brand and model number refrigerator you are asking about. We have no idea what RV you have nor what refrigerator you have.

X2 make/modelIs it Ammonia or Compressor. (big power and sound difference)You can usually look behind the outside vent and see how the fridge works. If the 12V lines are very small, like lamp cord, then it's a 2 way, (LP / 120v).Usually if it's LP, it's strictly Ammonia, which means 12V isn't a cooling option as it consumes 300-400 watts of electric power. (thats 33amps@12v or 3amps@120v) 12volt cooling fridges usually have a small compressor or small thermal engine (essentially a large cooler, but no freezer).

Long story but it is a Nor-Cold. Will post model and serial later. I'd hate to drive cross country on propane keeping fridge cold.

Fridge won't work on 12 volts | Good Sam Community

Mandalay_Parr
Explorer
Jul 24, 2014
87bob wrote:
I want to thank all the responders to my post. The main reason why I wanted to use DC while traveling is DC is cheap while the motor is running and the battery is being recharged. If gas usage is that low then that is great. I'll have to be sure to keep the tanks full while traveling.

DC is not cheap. It takes additional fuel for the additional elec load.

Jerry Parr
87bob
Explorer
Jul 23, 2014
I want to thank all the responders to my post. The main reason why I wanted to use DC while traveling is DC is cheap while the motor is running and the battery is being recharged. If gas usage is that low then that is great. I'll have to be sure to keep the tanks full while traveling.
Old-Biscuit
Explorer III
Jul 23, 2014
sh410 wrote:
87bob wrote:
How can I tell if my model is a AC/DC/LP it is a Nor-Col 982 Ser 005931CQBK6

That model will not run on DC. Service manual for Norcold 982

Correct......
It does NOT have a DC heater.
Strictly 120AC or LP
In 'auto' it selects 120V AC if connected to AC power source and will swap to LP when AC poser is not available.
If in 'manual' mode you can select AC or LP........but if either fail fridge will not swap to other heat source.
2oldman
Explorer II
Jul 23, 2014
mockturtle wrote:
I'd hate to drive cross country on propane keeping fridge cold.
Why? :h
x2
thomasmnile
Explorer
Jul 23, 2014
87bob wrote:
Long story but it is a Nor-Cold. Will post model and serial later. I'd hate to drive cross country on propane keeping fridge cold.

Like others posted and long story short, the common RV refrigerator available now uses a propane burner to heat the cooling unit and 12v DC power to run the control board. When on 110v shore power, the cooling unit switches to an electric heater for the cooling unit and the control boards still use 12v power.
FWIW, the propane consumption when operating the fridge isn't that bad, just depends on the ambient temp. the fridge has to cool down from.
sh410
Explorer
Jul 23, 2014
87bob wrote:
How can I tell if my model is a AC/DC/LP it is a Nor-Col 982 Ser 005931CQBK6

That model will not run on DC. Service manual for Norcold 982
the_happiestcam
Explorer
Jul 23, 2014
Popups usually have the three way, as those fridges are so small they can run on 12 DC. If your fridge has two doors on the outside (one for fridge, one for freezer), it is only LP/110.
While the amount of gas used is negligible, you can run for 4-6 hours on the hottest day with nothing turned on to the fridge - provided it is already cooled down, full, and the doors stays shut. I usually start my trip with it off then turn it on after gassing the TV later down the road.
87bob
Explorer
Jul 23, 2014
How can I tell if my model is a AC/DC/LP it is a Nor-Col 982 Ser 005931CQBK6
mockturtle
Explorer II
Jul 23, 2014
I'd hate to drive cross country on propane keeping fridge cold.
Why? :h
RoyB
Explorer II
Jul 23, 2014
My 2008 Starcraft 14RT OFF-ROAD POPUP came with the Dometic RM2193 for LP Gas, 12VDC and 120VAC...

We normally turn on the 12VDC when we are about two hours out from our destination.

Gives us alittle head start on getting fridge cooled down. Being the small cabinet height model we have to supplement this with our Coleman 5-day Ice Chest anyway...

Roy Ken