I am always being asked where the defrost timer is located on a
refrigerator. Unfortunately the location varies depending on the
manufacturer and model. Some are located in the rear near the
compressor. Others are behind the louvered kick-plate in the
front. Some are in the fresh-food section near the cold control.
To make finding them more challenging they are usually covered
except for a hole that allows them to be manually advanced. On
the refrigerator that I use the timer is in the fresh-food
section beside the cold-control. The only indication is the hole
that permits a large flat blade screwdriver to be used to
advance the timer. Fig 1 Typical Defrost Timer In a typical
defrost circuit 120 volts is passed to the timer from the cold-
control when it calls for cooling. The voltage energizes a clock
circuit. If the defrost timer is in the defrost position,
voltage is sent to the defrost heater circuit. If the timer is
not in defrost, voltage is passed to the compressor starting-
circuit and fans. Fig 2 Typic