Dometic fridge R&R

[groundhogy]

So, I have a used RV and inside it has a Dometic RM3804
refrigerator. Its propane and 12 volt I believe.

Its a 1990. so that's 25 years old.

should I just replace it?
or should I attempt to change out the guts of this thing?

I don't know how wonderful or not this fridge is, as I am
quite new to this.

any opinions?

[beemerphile1]

j-d wrote:

...EVERY RV fridge requires 12VDC for its control functions. It will NOT cool on ANY source if it doesn't have 12VDC to the electronic controls....

Not relevant to the OP's questions but your statement is wrong. They STILL use small refrigerators that do not require any 12vdc source. They are small and mostly used in pop ups.

I imagine a number of older vintage refrigerators also did not require 12vdc.

[pianotuna]

Hi,

Fridges that run on the ammonia cycle don't have compressors.

[beemerphile1]

groundhogy wrote:

...Seems simpler to just use Freon based like a normal refrigerator
and just run off electricity...

The best camping locations don't have electricity.

Does it work? If so, use it and be happy. It is probably better built than a new one purchased today.

[j-d]

Propane fridge has been around a long time. Most of the first home fridges (right after the Ice Box/Block Ice Age) were "absorption" like RV's still are. They used to be able to run totally free-standing. No electricity required. As I said, newer RV fridges offer electronic convenience (no lighting a pilot, no manual selection between LPG and electricity...) but at the expense of needing 12VDC to operate. The RV fridge uses very little LPG and has a low wattage demand on 120VAC. The test for a good cooling unit is based on using the 120VAC element, but many of us here believe cooling is actually better on LPG.
For a variety of reasons, some of which we can actually thank Momma Nanny Gov't for, Compressor-based fridges have gotten much more efficient (power consumption-wise) than they used to be. This puts those fridges within the power availability of an RV.
Some people have replaced a working RV fridge pre-emptively with an apartment fridge. I think most who have done it have done so because the RV fridge was inop or unreliable.
Yes, you can run one on a Solar/Battery combination. I have zero competence in how to size the solar panels, how many of what kind of batteries, etc. to use.
But I DO have a little competence in is limited RV fridge troubleshooting.
I'd suggest a little checking and troubleshooting to determine if what you have will work or is easily repairable. A well-cared-for RV fridge that age can still be serviceable. The killer of RV fridges is operating them off-level. Doing that causes the Cooling Unit to get blocked up and that isn't repairable.
Want to check it out? You'll need a Volt Meter, an old appliance cord, some electrical connectors, a couple hand tools, and oh, a Dollar Bill...

[groundhogy]

Yes, I think that's what size it is.

I was wondering, what is the big advantage of the propane option?
Amonia gas? seems complicated.

Seems simpler to just use Freon based like a normal refrigerator
and just run off electricity.
And.. sounds like you are saying an electric one can be run off
solar panels and batteries?

[j-d]

RV Fridges used to run on LPG, 120VAC, and had a "keep cool" 12VDC mode. Most newer ones, even 1990, are more likely to be LPG or 120VAC.

BUT!!! EVERY RV fridge requires 12VDC for its control functions. It will NOT cool on ANY source if it doesn't have 12VDC to the electronic controls.

I tried to find the dimensions of a 3804 and couldn't. If it's the typical "8 Cubic Foot RV Fridge" it's about 24" wide 24" deep and about 60" tall. If so, you can replace it with a "residential/apartment" fridge for under $200. Very little trim work required to fit it in. Then all you need to do is find a way to keep it closed on the road.

But that's best when you plan to go to campsites that have electric power to plug into. It'll hold cold for a day's travel if you don't keep opening it, and being compressor driven it'll recover fast once you set up at the campground. And yes, you can use one without a power source if you use Solar/Batteries/Inverter and/or a Generator.

RV fridge is pretty much three major components:

1. The Cabinet (doors, shelves, gaskets, etc.) - Think of a big Ice Chest
2. The Cooling Unit - all that piping stuff on the back
3. The Controls - Circuit Board, Wiring, Interior Panel.

If you can troubleshoot it, replacing the Controls or Cooling Unit will get you cold for half cost of a new RV fridge or less. Not cooling and Cabinet damaged, Replace. Cooling Unit AND Controls bad, Replace. Bad Cooling Unit and you can DIY the replacement, around $600. New RV Fridge (8-cft) nearly $1500.