RM2652 cooling unit on RM3604

[Jvand]

I’m considering replacing the cooling unit on my RM3604. The problem is the only cooling units I can find are over $600 (yikes, for a 35 year old fridge). I’ve seen very similarly sized fridges on Craigslist/offerup/etc. 

Does anyone know how interchangeable the cooling units are between very similarly sized fridges. I’m specifically wondering if the cooling unit from a Dometic RM2652 will fit on a RM3604. 

Thanks! 

[Jvand]

Thanks for the advice on this thread. I’m going to research purchasing a cooling unit built for the RM3604. 
my fridge is cooling but not able to get below 40*F in the fridge in the shade with the propane running all day. It will get colder on AC, so maybe that just means the flue tube needs a good scrub. 
I’ll clean the flue tube and then see how it does on propane before buying a new cooling unit. 

[StirCrazy]

another thing to look at is the space for air to flow around the evaporator (top fins of the cooling unit) there whould only be 1/2" of space between the walls and that forcing the air to move through the fins instead of around them.  another thing you can do is put a little fan in there above the fins sucking the air up to create more air flow and see what it does to your temps.  

[opnspaces]

Trying to follow your posts but it a bit confusing, When the refrigerator runs on any power source does it cool down? Or does it run for 12 hours and still not cool? I remember our long time member Doug Rainer who helped many people with refrigerator problems posting some good tests. The one that sticks in my mind to see if the cooling unit is bad is fairly simple. Below is his test.

CU = Cooling Unit

By hot wire he means the plug off an extension cord remove the tires for the 120v heater in the refrigerator and hook it straight tot he extension cord.

The best way to determine CU is to hot wire the 120 element for 24 hours. This bypasses the controls. IF the Refer does not get below 38 degrees, the CU is bad. DO NOT run more than 24 hours in hot wire. Doug
1. A BAD cooling unit will still get the freezer cold.
2. Yes, a Bad cooling unit can be replaced. Either a rebuilt/ OEM or a aftermarket (Amish) cooling unit. Depends on how much you want to spend. $500 to $1500 in the CU part only.

[StirCrazy]

are you thinking of buying an old used fridge and pulling the cooling unit off and putting it on yours?  wow thats some crazy thinking.

firstr off you are buying a used fridge in unknowna condition, anyone can say it was running good when they took it out, plus when the heating units go they were usaly good one day then  the next day they aren't that great.  so how long is that used fridge going to last in your unit, how many times did they run it out of level?  are there already crystals forming in the tubes?  did they just take a dead one and flip it upside down to move the crystals so it will work for another month or two? so many unknowens, then there is the work of swaping them over if they are compatable, generaly they are not.  you would have to go to a site that sells them and look up the two models and see if the replacment heat exchager is the same part number and measurments. 

I know up here its about 800 bucks for a new exchanger , about 2K for a brand new fridge and anything worh buying as a used fridge that I would put in my rv would be a 1000-1500 unit, to much work to take a chance on a cheepy.  and a new exchange basicly turns your 30 year old fridge into a new born, aside from the motherboard and usaly they cool better than when they were new.