It started a week or so ago. The fridge started getting too cold. It was OK on Propane but on AC any setting above 2 sent the contents into the ice age. At 3 the fridge was at 28-32* and the freezer was at 0. The Model is N641.3 Per the Norcold trouble shooting blog it was either the Thermister or the Optical Control Board. I opted to replace the Thermister at $25 vs the optical board at $188 to see if it would fix the issue.I ordered it on Wednesday and it arrived from Southern California tonight. It took 3 minutes to swap it out, no tools required. I set the fridge on AC and a temperature setting of 4. The temperature has been holding at 40 for 3 hours now. I am venturing that we have a solution. Photo new part number bag and old removed Thermister assemblylink for ordering Norcold Parts Norcold Parts ordering

$25 repair cost on a 8 yr old RV fridge..........pretty good.Freezing in food section thermistor is FIRST suspect. Either that have fallen off the fin and are hanging down, have been disconnected or just bad.W/O thermistor sensing fin temp thermostat doesn't get feed back so it allows fridge to run continuously.Surprised same didn't occur when using propane.......which could be that propane isn't 'heating' as it should. Dirty burner, dirty flue/flue baffle or low flame height

I should qualify the OK on propane comment. On propane I could keep the fridge from freezing at the 4 setting but just that, it was at 36.

Just went through the exact same thing and started as you did, but ended up with a new board also, to solve the issue.

well 12 hours have passed at the temperature is holding at 40*. This is good because we are leaving next week for a 9 day road trip, one less thing to deal with.

Could you post a photo of where this little gem is installed in a fridge?

When the Norcold Fridge goes PERMAFROST | Good Sam Community

Old-Biscuit
Explorer III
Dec 12, 2015
$25 repair cost on a 8 yr old RV fridge..........pretty good.

Freezing in food section thermistor is FIRST suspect. Either that have fallen off the fin and are hanging down, have been disconnected or just bad.
W/O thermistor sensing fin temp thermostat doesn't get feed back so it allows fridge to run continuously.

Surprised same didn't occur when using propane.......which could be that propane isn't 'heating' as it should. Dirty burner, dirty flue/flue baffle or low flame height
Buzzcut1
Nomad II
Dec 12, 2015
I should qualify the OK on propane comment. On propane I could keep the fridge from freezing at the 4 setting but just that, it was at 36.
jaycocreek
Explorer II
Dec 12, 2015
Just went through the exact same thing and started as you did, but ended up with a new board also, to solve the issue.
Buzzcut1
Nomad II
Dec 12, 2015
well 12 hours have passed at the temperature is holding at 40*. This is good because we are leaving next week for a 9 day road trip, one less thing to deal with.
deltabravo
Nomad
Dec 12, 2015
Could you post a photo of where this little gem is installed in a fridge?
Buzzcut1
Nomad II
Dec 12, 2015
noteven
Explorer III
Dec 12, 2015
Thanks for the post Buzzcut1.
deltabravo
Nomad
Dec 12, 2015
Thanks for the pic. I thought it was something that went in back side of the fridge where all the electronics and stuff were at. Pic helps!
jefe_4x4
Explorer
Dec 12, 2015
Buzz and others,
We had this problem with our garage refrigerator. The difference was it would just not keep things cool below about 20 deg. F and acted more like an insulation cavity. Oddly enough it was the same simple fix: fooling the sensor. Oh, and we insulated the garage, that helped too.
You going to Yosemite again for Christmas? Your post about a snowy camp in Yosemite is legend.
jefe
Buzzcut1
Nomad II
Dec 12, 2015
jefe 4x4 wrote:
Buzz and others,
We had this problem with our garage refrigerator. The difference was it would just not keep things cool below about 20 deg. F and acted more like an insulation cavity. Oddly enough it was the same simple fix: fooling the sensor. Oh, and we insulated the garage, that helped too.
You going to Yosemite again for Christmas? Your post about a snowy camp in Yosemite is legend.
jefe

Maybe:B