Part WP2188379, Defrost Timer, is a genuine OEM part manufactured by Whirlpool. The manufacturer describes it as "TIMER-DEF". Defrost timer. Turn the dial on the timer clockwise to advance it into and out of defrost. It is used in Whirlpool Refrigerators. Find appliance parts, lawn & garden equipment parts, HVAC parts and more from the top brands in the industry.