Why is it that most of the builds I see are putting this temperature controller in a separate "project box" outside of the fridge? Wouldn't it make sense to cut a hole in the door, wire the unit to the existing thermostat wires and have everything internal? That way you just plug the original power cord for the fridge in to the wall and you've got power for the whole system.
Here's why I ask....this is the picture of the schematic for my fridge that's posted on the back panel.
If I am understanding this correctly, the black wire is always hot when the fridge is plugged in. Only when the temperature triggers the thermostat, which closes the switch, is the red wire energized, thus turning on the compressor and cooling the system.
This picture is the inside, with the thermostat removed:
If I just cut a hole in the door, mounted the STC-1000, I could run the black wire to the STC-1000 power input, and one line on each of the cooling/heating outputs. Then I could run a (-) line into the fridge for the other side of the power input. The red wire is already tied to the compressor on one end, so I could just tie it to the second connection for the cooling section.
The only problem I see is making sure to insulate the hole I cut, but If I use some caulking or foam insulation it shouldn't be a problem. Am I missing something? Why don't more people do this? Why are so many people (like everyone) building these systems with additional plugs and exterior boxes?