Bimetal Defrost Thermostat WP4387503

Check for Video if any, watch 2X. The parts may look different (but not this time) Unplug.Defrost timer-dropped the control panel in the frig. the defrost timer sits right in the middle switch it out.Turn the timer to be set on the on cycle. Wasn't sure if the Bimetal thermostat was bad too so for a little over $20. I changed that too.- in the freezer- remove the metal panel and fan cover. its clipped on to the element tubing on the right. cut the wire. Splice the wire to connect the new one then cover with wire nuts. replace cover, plug in. use frig thermometer to verify temperature.

The first part I changed was the defrost timer but it did
not solve the problem, I replaced the bi-metal defrost sensor
and I have the same problem.

I can defrost by turning the clock manually and heater works.



























problem.

Watched the videos and made it simple.

I just replaced my defrost thermostat after using the place-in-ice-water method, and I think it may not have been necessary. My timeline: my fridge was not getting cold enough. I realized it the day before going on a trip. I vacuumed the (very dusty) coils at the bottom, and the next morning the fridge seemed colder, but I thought I should order parts just in case. I ordered a heater and a thermostat. The fridge seemed to be operating normally when I returned from my trip, but I had the parts, so I thought I'd go ahead and dismantle the freezer and test the existing parts. My intention was to return both parts if the old ones passed the tests. I opened up the back of the freezer and there was no ice on the fins. I thought, great, the existing heater works! I cut out the thermostat, placed it in ice water, and didn't get continuity. So I decided to go ahead and put in the new thermostat. Because I'm not experienced with using a multimeter, I thought I'd test the new thermostat to see how the test should work. To my surprise, the new thermostat also failed the test! Stumped, I thought I might as well install the new thermostat, since I had opened the package and couldn't return it.
Further internet research suggests the place-in-ice-water method of testing is not adequate. One YouTube video by Parts Dr says to place the part in a working freezer. I froze my old thermostat and tested it; still no continuity. This thermostat may not be typical, though. The video discussed the temperature ratings on thermostats. The temperature rating on both (old and new) thermostats is L8.9-16.7C. That converts to 48-63 degrees fahrenheit, which obviously are not freezing temperatures. I'm not convinced I needed a new thermostat, but I trusted the videos I consulted earlier.
I cleaned the fridge thoroughly, so at least now I have a nice clean fridge to show for my efforts.

followed directions

After watching videos how to replace went very easy.removed ice maker cut wires replaced switch put back together now working ok so far.

Basically, I read all of the remarks from other people that had the same problem , I replaced both the timer and thr defrost(bi metal) thermostat as the thermostat had a ohmic value when closed that I was not comfortable with. The unit is now up and running and defrosting as it's supposed to do. I could not get those pushdown clips that hold the timer unit , I ended up breaking them off at the plastic post but there was enough of the plastic post showing that a bit of hotmelt glue was able to hold the timer secure.

After unplugging the refrigerator, I used a hairdryer to melt the ice sufficiently to be able to remove the freezer rear panel with a nutdriver. I also removed the ice-maker for easier access to the components behind the panel, using a nutdriver. Once the panel was removed I melted more ice at the bottom of the evaporator housing. After partially melting the ice in the drain tube, I poured hot water down the drain tube until it cleared, signaled by the sound of the water dripping into the drain pan. I next removed the clip-on Bimetal thermostat from the copper line going into the evaporator and snipped the two wires to remove it. I installed the replacement thermostat with crimp-style connectors and pull-tested them. I also replaced the timer board that is located below the freezer, below the top shelf, using a nutdriver. I replaced the circuit board as a precaution that the thermostat may not have caused the problem. I didn't change the heater inside the freezer as it checked out to have the same resistance as a new one. I tested the removed thermostat using a glass of ice water but it remained in the open condition, using an ohmmeter. (I later checked that thermostat after the freezer was running and it did close, and returned it to the open position by heating it under the hot water faucet. I suspect that it didn't work properly, or the timer control board was faulty). After re-installing the back panel and ice-maker and plugging the refrigerator into the power receptacle, it worked very well, and has done so since the repair.

I first disconnected the power cord and then removed all the panels and disconnected the Defrost Heater at the quick-disconnect, and cut the wires on the Defrost Themostat. (The Defrost Thermostat had been replaced about 10 years ago when the Defrost Heater was replaced.) One of the reasons it took longer than 15 minutes was because there was a buildup of ice in the freezer section. I then soldered the wires and covered them with a plastic sleeve and wrapped them in electrical tape. After replacing all the panels and re-connecting the power cord, I restarted the refrigerator. After one week, there is no water dripping from the freezer and everything is working properly. Your diagnosis of the problem was exactly right. Thanks for the info.

Pulled frig away from wall, installed part accoding to instructions...no more problem. HOORAY!!!