We had a problem with our refrigerator getting too cold even on the lowest setting. The fins in the refrigerator were also frosting over very heavily. After doing some research online we think we have found the probelm. The thermistor located on the fins seems to be failing. We tested with an ohms meter and it was not testing as it should. We have replaced it and at this moment all seems well.
The important thing is that we found the Service Manual online. It is very good for troubleshooting the refrigerator. It is athttp://bryantrv.com/docs2/docs/ncoldnnewnseries.pdf
When you click on the link it will download the manual.
Update: The new thermistor is working great after 8 hours. The refrigerator is keeping a nice steady temperature!!!