Absorption refrigerator

[Zayvier]

Hi. I just purchased a 1976 dodge chinook 18 plus 2. I am checking the absorption refrigerator right now.

It is Dometic Model RM 66E or RM 66.
It is missing the bottom left has lighting push in knob. So I was able to light it manually from the outside of the rig on the backside of the refrigerator. The flame is nice and wide and blue. I’m letting it sit overnight to see if the refrigerator actually cools down. If it doesn’t then I guess it means that the absorption system has issues- rust, ammonia leaked or crystallized or ....?

If the system does work then next is to try it on shore power. Then on 12volt power.

Do the both electrical systems (110v and 12v) both use the same mechanism to heat up the ammonia?

Is it possible to run this refrigerator completely on 12v?

Can I use a new car battery as the house battery for the RV 12 volt system or must I change it to a few cycle battery?

If this refrigerator works for 110v/12v/LP......is the u it itself inefficient because it is form 1976 or no ? A burning LP flame is cheap as well as a 12v heating unit is a low draw in the battery?

Thanks,
Charlie

[chin_k]

DC is drawing a lot of current, so it will deplete your batter(ies) quickly. If you check the DC panel, the largest wire in there is probably going to the fridge. LP is most efficient. AC use a different heating element, and if you get your hand on the manual, most likely it will list a different wattage for AC vs DC due to that. You can also verify it on the schematics.

Regular car battery is for cranking the starter. It is for short period of large current draw, then immediately starting charging up from the alternator. The deep cycle battery allows deeper discharge before getting damaged, but allows for a smaller current, so it is not really for starting your engine. You can replace one with another, but not ideal.

[Zayvier]

Thank you for your reply. I’ll check panel, change the house battery to deep cycle, and check the wiring schematics.

[Zayvier]

I ran the fridge on propane last night and the freezer was at -8 degrees. The fridge could be colder but I realized that the previous owner replaced the fridge outside panel with one that is solid and does not allow for airflow. So we are not getting air intake and up and absorbing the heat and leaving. So I left this panel off and will see if the fridge section gets colder

[Jlfchinook]

Looks like the system is still charged, it should stay the same temp on 110 power. You may be able to replace lighter with one used on propane grills, if you can not find parts for original.