the thermistors can be checked at the mother board on the back of ref. remove cover to gain access. unplug the ref. at the upper right hand corner of the board there will be a connector at j1, this is written beside the connector. remove the connector. thermistors read anywhere between 2k and 80k ohms. set your meter to a high scale. on the connector from left to right, count five positions over, first opening in connector may or may not have a wire, count this position anyway. place black meter lead into the 5 position. place your red lead into the the first wire. ohm reading should be 4k to 10k if good, 13k to16k if bad. move your lead to the second wire and readings should be close to the same as the first wire and same conclusions. these are the two refrigerator side thermistors. one is located at the damper and one is located close to the bottom of ref. if one checks bad, replace them both. ge had some sensor problems in the past. if both thermistors check good then you could have a bad damper motor or mother board. to determine damper motor, unplug the ref. wait 60 seconds and plug back in. watch the damper for a minute or two and see if it moves. it should move as this is a self test at startup. to double check the motor if it does not move, take the damper out and ohm thru the motor. if it reads any ohms the motor is good, if it reads open it is bad.