Kitchenaid KSRS25IKSS01 evaporator fan not running, freezer/fridge too warm

[petrelline]

Model Number

KSRS25IKSS01

Brand

KitchenAid

Age

More than 10 years

This is a fairly old side-by-side Kitchenaid refrigerator. Initial symptoms were the refrigerator getting warmer, and then the top part of the freezer (including the ice maker) defrosting. The bottom part of the freezer stayed frozen. The compressor is running continually.

We emptied the freezer and took the back inside panel off and the coils were frosted up (not excessively, they look normal) but the evaporator fan is not running. There is no power to the fan, but it works fine when disconnected and 120V is supplied. We left the fridge overnight to defrost, turned it back on and the coils frosted up just fine -- but the fan is still not turning.

We're not sure where to go from here. Husband suspects there is something wrong with the thermistor, but I thought the thermistor was just for defrosting, not for running the evaporator fan. Help?

 

[Jake]

I'm attaching the schematic sheet below, Look at #3(red wire) on the electronic defrost control, that powers the evaporator fan motor, through the #1 terminal(red wire) on the air baffle assembly, then goes to #2 terminal(red/white) on the same air baffle assembly, then to your evaporator fan motor per the refrigerator thermostat contact.

So, if that refrigerator thermostat: Temperature Control Thermostat WP2161460 ohms good, then its either the electronic defrost control not sending 120 volts to the to air baffle, thus to the evap. fan motor, or your air baffle has a broken circuit in it, or you have a frayed/broken wire between the red/white wire and white wire that go directly to the evap. fan motor.

Here's the electronic defrost control for your model, if needed:
Defrost Control Board 4388932


Here's the air baffle for your model for your model, if needed:
Diffuser WP2209751