Norcold 682IM not cooling

[Gjac]

I turned my 20 year old Norcold refer on Mon on electric it cooled down to 40 degrees over night on the setting of 3(1-5), but later rose to 50 degrees. I raised the setting to 5 which is the max which did to help. Ran it on propane for 4 hrs but that did not lower temps in refer box. Freezer was reading 10 degrees and refer was reading 54 degrees outside temps were 74 degrees. No ammonia smell or yellow powder, so I was fearing a blocked cooling unit. I wired the heating element to 120v overnight bypassing the control board and refer read 34 this morning, fin temps were 18 degrees. So I assumed the cooling unit was still working as it should. Can a bad thermistor cause this problem? Any other simple checks that I can make?

[Gjac]

Dinosaur had no replacement thermistors, nor did PPL or a few other places that I called. While waiting for these places to get back to me I decided to check and clean the connections on the control board, power supply and eye brow on top of the refer. I found some corrosion on the eyebrow connection, cleaned it and reassembled and ran the test again overnight with the thermistor connected to the fin and the temp setting on 5(max setting) and the refer temp got down to 34 degrees. I set the eyebrow switch to 3 and ran it again overnight and temps were 36 degrees this morning. The moral of the story is even a new thermistor with not work with a bad connection. I am just grateful it was not a bad cooling unit.

[dougrainer]

crasster wrote:
Another fridge problem! My vote is thermister but be sure to check all coils for dust.... Or go with a home/dorm fridge (they work!)

So, there are no Service centers or Service techs at all for home type refers??????? They are SO GOOD, they never fail? We have them out at least once a month to fix residential's in the RV's and the Residentials are a distinct MINORITY in the RV's we sell. Doug

[dougrainer]

I would talk to Dinosaur and see if they have an aftermarket replacement. Also, having the refer run 24/7 is not going to harm anything. Doug

[crasster]

Another fridge problem! My vote is thermister but be sure to check all coils for dust.... Or go with a home/dorm fridge (they work!)

[Gjac]

I disconnected the thermistor and let it hang as Doug suggested and ran it overnight at max setting of 5. the refer temp was down to 31 degrees and the freezer was down to 0. The outside temps were cooler last night about 60 degrees. The average fin temp was 20 degrees. I noticed that refer temp seems to be about 10 degrees higher than the fin temps in running these tests. I called Norcold for a replacement part number but they said the refer was obsolete and could not find a replacement part for it, they wanted me to buy a newer 1200 model. Does anyone know of a replacement thermistor and part number and where to buy one? I would just like to cut the end off and splice to the old wires and clip it back to the fin.

[dougrainer]

The clip is just to hold the bulb on the fin. I would snip and splice the new bulb instead of trying to route it to the board. I have never done that, but, most Norcolds, that wiring is foamed into the refer cabinet. Dometic's you have to pull the refer and then replace the complete Thermister and wire. Newer Norcolds have a quick connect clip by the interior light to make replacing a lot easier. Doug

[Gjac]

dougrainer wrote:

Gjac wrote:
Thanks Doug, if I remove it from the fins and let it hang, will that have the same effect as turning the refer to the max setting of 5? Also I see nowhere to disconnect thermistor inside the refer does this have to be disconnected from the board in the outside compartment? If I understand your post, if I disconnect it and it works(cools properly) the thermistor is bad if it fails to cool with the thermistor disconnected does this point to a bad control board?

Never seen a control board affect the cold operation. Of course I have only worked on RV refers for 37 years:B Letting it hang will cause it to work and cool 24/7. Doug

Thanks. I assume the clip just holds it in place to sense the temp of the fin and the fin to clip is not a ground is that right ? How is this replaced I see wires going into the back of the refer,no disconnect inside . I assume this must attach either to the board or eye brow somehow but I can't see how. I see something call "snip the tip" where the new one is just wire nutted to the old wire. Is this a good way to go?

[dougrainer]

Gjac wrote:
Thanks Doug, if I remove it from the fins and let it hang, will that have the same effect as turning the refer to the max setting of 5? Also I see nowhere to disconnect thermistor inside the refer does this have to be disconnected from the board in the outside compartment? If I understand your post, if I disconnect it and it works(cools properly) the thermistor is bad if it fails to cool with the thermistor disconnected does this point to a bad control board?

Never seen a control board affect the cold operation. Of course I have only worked on RV refers for 37 years:B Letting it hang will cause it to work and cool 24/7. Doug

[Gjac]

Thanks Doug, if I remove it from the fins and let it hang, will that have the same effect as turning the refer to the max setting of 5? Also I see nowhere to disconnect thermistor inside the refer does this have to be disconnected from the board in the outside compartment? If I understand your post, if I disconnect it and it works(cools properly) the thermistor is bad if it fails to cool with the thermistor disconnected does this point to a bad control board?

[dougrainer]

Yes, a bad Thermister can cause the problem. A BAD Thermister will still test(OHM) out correctly. Only way to tell is to replace it. OR, remove from the fins and let hang. Doug