A:Answer A parts list can be found here: http://www.whirlpool.com/digitalassets/MLPDF/Repair%20Part%20List%20-%20W10813504.pdf
See page 18, Air Flow Parts. There is one air flow motor and fan (see #7 and #8). Air moves from the bottom of the freezer, through the evaporator (to cool it), through a duct (#5). The cold air either returns to the freezer (see the top left of the duct) or travels to the refrigerator (see the top right of the duct). The cold air enters the refrigerator via a diffuser (see #7 and #8, on page 4, Refrigerator Liner Parts).
Temperature is controlled by a thermostat (see #9 and #10, on page 20, Control Box Parts) and a control knob (see #15 and #14) which moves a connecting rod #22. The connecting rod adjusts the amount of cold air from the freezer allowed to enter the refrigerator through the diffuser (discussed above).
You want the freezer to be slightly above zero F, and the refrigerator to be slightly above freezing, say 35 F. When the compressor is running, the top shelf does get colder than the remainder of the refrigerator because the diffuser is on the top left. However, once the compressor stops, cold air sinks (heat rises) and the shelve temperatures tend to equalize.
