DAMPER COVER Assembly WR13X10988

The refrigerator side freezes. I replaced the thermistor at the damper control assembly. No change. I tested the old thermistor for ohm readings and they are good for cold and room temperatures. I took the damper control assembly off noticing there is nothing in the assembly that controls the plastic flap which swings freely. There are 2 wires that come up to the assembly from the control board and terminate at a module in the assembly. Two wires come out of the module to the thermistor and 2 go to the light. There is no motor inside the assembly to regulate the damper. What controls the damper and why is the assembly so expensive if it is just a plastic shell?

On my side by side refrigerator freezer, the refrigerator does not get cold enough. The freezer works fine. The refrigerator gets to 50 to 54 degrees. Reading your help page i decided to take off the vent housing on the upper left wall inside the refrigerator. So i have a bigger square hole in the wall. The temperature went down to 40 degrees. Hurray. I reassembled the the vent housing and the temperature went back up to 50. Took it off and again went down to 40. Looking at the vent there is no sensor only a plastic flap that does not show up on the parts diagram. The flap swings on three plastic hinges. I can not see any damage at all on this housing. Do i need a new plastic flap? Thank you john macleod

Re your response to my question of the damper control assembly, does the assembly wr13x10988 also include the motor? In your response you said it would include the thermistor, bulb, socket and cover.