Refrigerator Defrost Board

Several screws held panel concealing defrost timer to roof of fridge compartment, unplug unit, (very important) remove screws to get to timer, unscrew mounting screws & unplug wiring harness, reverse to mount but this did not fix my problem, had never seen anything else cause this problem but after looking at wiring diagram & seeing that ... Read more the bi-metal was normally in closed position under 52* & also seeing that at that temp. the bi-metal open circuits & takes fridge out of defrost mode I was quite sure I had misdiagnosed or actually guessed & not diagnosed at all, purchased a bi-metal & removed the cover in the freezer covering the evaporator & replaced the bi-metal by cutting, stripping the wires & securing new part with wire nuts (always pull after twisting to be sure nuts are secure) plugged unit in and about a day later I heard ice cracking sound coming from the freezer & knew it was in defrost mode, also back cover covering evaporator was warm, It was fixed & was really glad to not have to remove cover in freezer every couple of days to defrost it with a hair dryer, diagnosing bi-metal for an ohm reading while below 52* could have saved me over a hundred dollars that the timer cost but now have a spare timer, good luck with your repairs