Need help with fridge issue

[ClaytonRanch]

I have a coachman travel trailer with a Dometic rm 2852 refrigerator. This particular model doesn't have a thermostat. The problem is that it is freezing everything in the refrigerator section. I have tried and tried adjusting the thermistor per a similar post here to no avail. I can't seem to get the temperature to stabilize. Anybody have any suggestions? I've also seen add on thermostats. Has anybody ever used one of these and are you satisfied with the results? Thanks as always.

[ahicks]

No experience with this model fridge, but did see something similar on another where the sensor was not firmly attached to a cooling fin? It was just hanging there.

[hnybare]

Some of those have an adjustment "screw" in the board mounted in the outside compartment where the ref controls are. You might ck and see if you have that and can adj. Also on the board you might insure the thermistor connections are snug. It could be the thermistor has failed.

[ga traveler]

I don't know what the previous post advised, but the factory told us to move the thermister to another fin. try moving from top to bottom of fin. Right to left. If this doesn't work, change the thermister.

[GaryKD]

Hi ClaytonRanch,
Welcome to iRV2.
Remove power from the refrigerator before testing the thermistor. I just went through a similar problem. Are you comfortable working with a VOM meter? If to, it is easy to check the thermistor. To test the Dometic thermistor, disconnect it from the circuit board and place the other end (sensor end) into a glass of ice water. After a few minutes you should be able to get a resistance reading of 7,000 to 10,000 ohms between the two terminals of the connector. If the resistance isn't close to those numbers, it is bad.

To do this one must remove the thermistor from the slider it is mounted on. Do this carefully. Thermistors are very delicate. Remove the cover from the power control board. Unplug the thermistor connector from the board. Follow the above mentioned test steps.

There are some other simple things one can check:
1. Is the symptom the same when powered via propane or electric?
2. Is the thermistor on the right most fin.
3. Is the bottom of the thermistor slider about 1/2 way up the fin?
4. Is the thermistor securely in the slot made for it, completely enclosed by the slider?
5. When the bottom of the slider is about 1/2 way up the fin, is the thermistor part of the slider still on the fin?
6. Moving the slider down will raise the temperature. Moving the slider up will lower the temperature.

Please post the results here.