A Refrigerator Modification

I bought a couple of wine coolers from Home Depot a few years ago. They look nice, the inside is big enough to hold 2 of my kegs, and it was pretty easy to put a tap tower on top.

However, these are wine coolers. I'm actually using one for wine, so it's just fine, the other I'm using for beer. The problem with the wine cooler part is the temperature really only has two settings, one for red and one for white. The lowest the temp will go is 39F, which is just okay for beer. Personally (and this is definitely an area of personal preference), I like my beer served at 34F. It will warm soon enough in the glass all on its own, especially on hot summer days. So -- I modded it to run at a lower temperature. This was a pretty straightforward project after a little internet search.

My approach is to replace the built-in temperature controller with an Inkbird:

These go for about $35 on Amazon. I have one just like this that I use to run the freezer I use for fermentation. They are very easy to set up and work very well. There are 3 wires, the one on the left is for the temperature sensor, the middle turns on electricity to both a hot and a cold device, and the third is for the power. In this case, I don't need the hot, just the cold. In my fermentation freezer, I have the power cord for the freezer plugged into the cold and a terrarium heater for the hot.

Next, I found the circuit diagram for the wine cooler pasted to the back, it looks like this:

Wine cooler circuit diagram

If you look closely, the wires are labeled with colors, so all I have to do is cut the brown and red wires from the circuit board and connect them, which bypasses the built-in controller completely. This does mean that the internal light and temperature display won't work, but I don't care. The built-in controller is located on the inside ceiling of the wine cooler, and it's held in place by 2 screws. Inside is the circuit board, which looks like this:

Wine cooler circuit board

The brown and red wires are in the lower left corner of the picture. I just cut them and used a wire nut to connect them. The blue wire powers the compressor, so it's essential to leave it alone or the fridge won't cool at all.

There is a drain hole inside the fridge right above the compressor. I widened it a little with a drill and was able to push the Inkbird sensor inside with no problem, so no chance of hitting a cooling line. I ran the sensor up to the built-in controller and used some black gorilla tape to hold it in place.

That's it. I set the temp on the Inkbird and since there is plenty of room behind the rear access panel, I put all the wires and the Inkbird behind the panel, so it all looks like it was never modified.


April 24, 2020: Both of the coolers have crapped out.
Model MCWC50DST
The beer fridge needed 2 parts:
HQRP QP2-4R7 4.7 Ohm 3-Pin PTC Starter/Start Relay Replacement for Mini Fridges, Compact Refrigerators, Beverage & Wine/Beer coolers, Deep Freezers, Beer/Wine Refrigerators
Danby 1.03.01.01.117F B57-120 OVERLOAD PROTECTOR
These were both pretty easy to install.

The wine fridge is showing an EEF code. The beer fridge didn't show any code because I've done the modification above. Those parts look fine on the wine fridge, so I'm going to attempt the same modification as the beer fridge to see if it's the temperature controller that is out. Update -- that didn't work. It seems the best the fridge can do is about 53 or 54F, and it runs all day to keep it there.  A new fridge is on the way.