Fridge Thermistor Upgrade (7/24/2013)
Even with all the fans (internal and external) that I added to our Dometic NDR1292 fridge and the fridge’s temp control maxed out at “5”, the inside temperature still hovered around 40° F — the top end of the safe fridge temperatures.
So I looked into ways to bring the temp down and found two methods that use an adjustable thermistor. In a Dometic NDR1292 (and other models), a thermistor mounted on the cooling fins is used by the fridge to determine how cold it is. The thermistor used inside our Dometic NDR1292 is “fixed”, that is, the thermistor resistance is not adjustable.
The two methods I discovered change our Dometic’s fixed thermistor into an adjustable one that allows you to change the temperature. Specifically, both fixes allow you to lower the temp inside the fridge beyond the original settings.
The first fix, called Snip-The-Tip, required removing the end of the original thermistor and then attaching a new adjustable thermistor. This looked appealing at first, but I wanted something less “invasive”.
To install, I turned off the fridge, removed the cover from the black box control board, unplugged the connection to the original thermistor, and then connected the Dinosaur Thermistor Adjustor to the original thermistor and to the control board. That’s it — besides setting the “Colder”/”Warmer” dial. (I set mine to maximum cold.)
Finally, the “proof is in the pudding” and after a day of letting the fridge temp adjust, the “new” temp inside our Dometic was 34° F: