I have a basic question I can not find the answer to. I have a Dometic 2 way fridge (propane/120volt) in a 1985 Airstream. I can not get the fridge to run on either 120 volts or gas. I do not have a battery at this time.(I am on shore power)Do I need a battery to run the fridge even though I am hooked up to shore power? Is the battery required in order to "complete the circuit"? I assumed since I am on shore power the fridge should work either way even though I do not have a battery.

Pretty sure you need a battery for the electronic parts, would think you need battery to light up the propane, I am sure you will get a proper response shortly.

You do need 12v for the control board in order for the refrigerator to work. If you have a working converter or battery you should be good.

You need 12v to run the fridge in either AC or gas modes. You can get that 12v with no battery from your converter (makes 12v from 120v) but in the 1985 Rv, not sure how that works.You could get a battery, but also you need a way to recharge it, so a simple deck mount converter in addition would be a help if the 1985 converter has no charger to it.In theory you could get a battery and just use any battery charger to recharge it as required, but that could be tiresome, so a converter that stays on would be preferable IMO.

Solar is the easy way to keep a battery charged.

Yes, you need 12v to power the control board in the fridge regardless if running on 120v or gas. As long as the converter/charger in the trailer is putting out 12v you shouldn't need a battery.However, some older converter/chargers won't put out 12v without a battery in the circuit. If this is true for yours, you won't have any 12v power at all. If you other 12v items working like the water pump, interior lights, and radio, then you have 12v in the trailer, and the fridge issue is likely either a fuse of bad control board.There are tons of YouTube videos on diagnosing an absorption fridge...you want to diagnose well because it gets expensive in a hurry if you just start throwing parts at them.

2-way refrigerator operation without a battery | Good Sam Community

BFL13
Explorer II
Sep 25, 2020
http://techsupport.pdxrvwholesale.com/wp-content/uploads/2017/09/Dometic-Refer-Model-RM2820-Installation-User-Manual.pdf

Seems a 1985 airstream will have a Dometic 2820 two way as OEM. (some googling to find that)
MEXICOWANDERER
Explorer
Sep 25, 2020
If the unit has any pilot control lights outside, then you need 12 volts for it to run.
dougrainer
Nomad
Sep 25, 2020
vintage 1985 is just when Dometic came out with the AES model refers. AES stands for Auto Energy Select. They had a an ON /OFF switch with an indicator light. MANUAL Dometic Models, you had to HOLD the Pilot button and then continually push a Manual Piezo lighter button. If the OP has just an ON OFF switch, then he has an AES and requires a 12 volt source to operate. If he has to push in a button and then continually push the LIGHTER button, he does not need a 12 volt source. AS always, MODEL is required to correctly answer his question. Doug
pauldub
Explorer
Sep 25, 2020
What model is the fridge??? My '81 travel trailer had a fridge that did NOT need 12V to operate.
BFL13
Explorer II
Sep 25, 2020
https://www.airforums.com/forums/f449/wiring-new-converter-from-12-volt-panel-101990.html

Says what the 1985 converter is/was. In a video that came up (googling) it showed the converter in an older Airstream. That converter looked a lot like the OEM one that was in our 1981 truck camper. It was a real beast, made in Winnipeg to a British design--forget the brand name for it.

It did supply 12v when plugged into 120v. It had a battery charger section too. It made loud clunks when it switched. It was very big and heavy. Got rid of that and used a modern converter instead.

bestconverter has an article about Airstream converters. Also something on how to keep the OEM power- on indicator light working if you do swap out the old converter.

An old thread about it--it's a Magnetek 730-2

https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/13748154/print/true.cfm
pianotuna
Nomad III
Sep 25, 2020
dedmiston wrote:
Lwiddis wrote:
Solar is the easy way to keep a battery charged.

He's on shore power, which is even easier.

Shore power is more expensive if you are camping.
dedmiston
Moderator
Sep 25, 2020
Lwiddis wrote:
Solar is the easy way to keep a battery charged.

He's on shore power, which is even easier.
time2roll
Nomad
Sep 25, 2020
What is the voltage getting to the fridge control board?
Does the light in the fridge work?
Is this an auto ignition fridge or do you light the pilot manually?
Dutch_12078
Explorer II
Sep 25, 2020
The common Magnetek converters from that era used the battery as part of the filter system to regulate the 12-volt output. Without the battery the voltage typically runs too high and may cook some fuses. Even a cheap lawn tractor battery will work well enough to operate the fridge.
enblethen
Nomad
Sep 25, 2020
What model is the refer?