Refrigerator Circuit Board replacement

[gordinho80]

Previous Owner of our camper, 2000 Coachmen Futura 2790TB, indicated that the circuit board for the fridge would need to be replaced. I'm looking into this and noticed a loose wire from the board, blue wire in picture. Any idea where this is supposed to go?


Larger Image - https://photos.app.goo.gl/11ZLhbZnuRTCSNEz1

[Old-Biscuit]

Sodium Chromate is the anti-rust inhibitor used in the coolant solution.....Ammonia, Water, Sodium Chromate and Hydrogen Gas

When cooling unit has a leak the Sodium Chromate is that yellow residue.

DEAD!

Nothing to do with the circuit board.

[Boon_Docker]

gordinho80 wrote:
Is it possible that the yellowing is a result of the circuit board failure? And that with a new board and a cleaning, it could work fine?

No, the yellow staining is at the bottom of the heating unit not the bottom of the circuit board. This means that the boiler has sprung a leak, the yellow is from the sodium chromate that has leak out.

If in fact I am looking at replacement, I'm looking into residential units. I consider myself handy enough to handle replacing the cooling unit if need be. But I don't mind considering the residential electric unit.

Right now, we're not planning on going out off the beaten path or boondocking for anything longer than a day or 2. Future mods include solar panels, large battery bank, and perhaps a small generator for emergencies.

[BadgerMcAdams]

gordinho80 wrote:
Is it possible that the yellowing is a result of the circuit board failure? And that with a new board and a cleaning, it could work fine?

No, that yellow powder is an indication that your cooling unit (the part that looks like a still) has sprung a leak somewhere and has started leaking (or lost) the ammonia coolant that is used to cool down the fridge.

Your options are to either One, replace the cooling unit (and maybe the circuit board) which if you are not mechanically inclined can be tough. There are videos on YouTube about it, and if you are mechanically able, the cooling units can be less than half the cost to replace the fridge with an entirely new unit.

Two, to replace the entire unit with a new 2 or 3 way RV type fridge. While it will work for you as it should, the ammonia fridges are very susceptible to damage from being out of level when running. There are many threads on this forum about the damage that can be caused.

Three, to replace the fridge with a residential fridge (i.e. a 110 volt "dorm" fridge) which means you can only run it on either shore power, a genset, or a power inverter (which will still require a way to charge the batteries as this will eat power)

or Four, replace the Old fridge with a Danfoss Compressor 12v/110v fridge (like what is used in marine applications and over the road Trucking). The price for this is about the same or comparable to a 2 or 3 way fridge. They do use battery power, but not nearly as much as a Resi-Fridge would on battery/inverter operation. The Danfoss fridges also are not bothered by out of level campers the way the ammonia fridges are...

The choice is yours...Wish you luck on it...

I'll probably have to be changing the one out in my TC soon...So I am right there with you.

[turbojimmy]

gordinho80 wrote:
Is it possible that the yellowing is a result of the circuit board failure? And that with a new board and a cleaning, it could work fine?

Sadly no - the coolant has leaked out. On the bright side, it didn't ignite. It's also highly flammable.

You'll have to decide which path to go depending on your intended use. If you'll be plugged in all the time and/or have a big enough battery/solar setup then maybe you don't need an RV-type fridge.

I like being able to keep the fridge running on propane while traveling (that's a whole nother topic of debate that I don't want to get into). Some of my camping is at NASCAR and other events where there are no hookups. Yeah I could run my generator but it's a lot less efficient than using the propane setting on the fridge (and etiquette dictates shutting it down at night). Plus the fridge is much cooler on propane, though this might not be the case with everyone.

[wrgrs50s]

The yellow cake like stain is the ammonia mixture from the cooling unit leaked out. The circuit board would not cause that.

To confirm that the cooling unit is fried you coud unplug your heating element from the circuit board and rig up a 2 prong plug on the end to plug directly into an outlet and if the element is good it will start heating the tank. You will know within an hour if it's ok. That yellow only comes from one place and that's the cooling unit. When it's fresh it has a distinct ammonia smell.

[gordinho80]

Fair enough. Thank you.

[ksg5000]

Your previous honor was either ignorant/dishonest. As others have indicated that looks like your fridge has lost it's coolant (yellow powder). Your choices are to replace the cooling unit (many prefer Amish) or replace the entire fridge. Lots of threads on both subject - use the forum search feature.

[gordinho80]

Is it possible that the yellowing is a result of the circuit board failure? And that with a new board and a cleaning, it could work fine?

If in fact I am looking at replacement, I'm looking into residential units. I consider myself handy enough to handle replacing the cooling unit if need be. But I don't mind considering the residential electric unit.

Right now, we're not planning on going out off the beaten path or boondocking for anything longer than a day or 2. Future mods include solar panels, large battery bank, and perhaps a small generator for emergencies.

[turbojimmy]

Yeah the circuit board is the least of your worries there. You need a new fridge. If you want to keep the convenience of an RV-type fridge (can run on propane) then you're either going to have to completely replace it, or replace the cooling unit (and the circuit board assuming it's bad, but I think the previous owner might have pulled a fast one there).

If you're handy, a cooling unit replacement is a cost effective way to keep the convenience of the RV-type fridge. You just change junk on the back of the fridge and keep the "box", AC heating element and propane plumbing/heater. The fridge has to come out and be disassembled. I did mine inside the rig and popped it back in.

[coolmom42]

wrgrs50s wrote:
Not sure about the blue wire but the yellow stain indicates a cooling unit failure as newman fulltimer suggested. I wouldn't waste any money on a new circuit board.

I've seen where some folks have decided to change out the old fridge with an all electric fridge that's close enough to the same size, and do a little trim work to make it fit. It's a lot cheaper than a gas/electric.

I would go with a 12 V swing compressor type fridge. Very efficient, cheaper than an ammonia fridge.

[wrgrs50s]

Not sure about the blue wire but the yellow stain indicates a cooling unit failure as newman fulltimer suggested. I wouldn't waste any money on a new circuit board.

I've seen where some folks have decided to change out the old fridge with an all electric fridge that's close enough to the same size, and do a little trim work to make it fit. It's a lot cheaper than a gas/electric.

[newman_fulltime]

it goes nowhere its a factory wire but seeing all that yellow your fridge cooling unit is toasted

[gordinho80]

OK, thanks! I'll replace the board and see how things go!

[newman_fulltime]

it goes nowhere its a factory wire