Now that you have the control housing out of the refrigerator, remove two quarter inch screws that hold the timer to the housing. Flip it over and remove the timer out of the housing. There is a 4-pin connector that attaches to the defrost timer. Use a flat blade screw driver to pry between the connector and timer. Discard the old timer. Plug the new timer into the harness. Position the new timer into the housing and replace the two quarter inch screws. The defrost timer has a dial that will only turn in a clockwise direction. Using a flat blade screwdriver, turn it until you hear a loud click. The click indicates the beginning of the defrost cycle. Turn it a bit further to take it out of the defrost cycle so the refrigerator will cool.
Now you’re ready to reinstall the housing. Reconnect the wire harness. Attach the control housing and reinstall the screw. Reattach the air diffuser and the screw. Reinstall the light bulb. Reattach the light cover and knob. Now you are ready to reconnect the power. Your repair is complete.