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I have a defrost timer brand new but it won’t go in defrost mode I have to do that manually and it will come out of defrost, but what I notice when the timer is in cool mode. only pin 1 and 2 which is defrost mode getting power and when I check 1 and 4 getting nothing which is cooling mode, and also the coil which is 1 and 3 nothing also, the thing is when I turn off the thermostat that where 1 and 3 getting power and I can hear the motor moving and the timer would advance normally but that when the thermostat off I don’t know if the thermostat is bad but I am getting conunity on the thermostat
Hi, The wiring diagram in the tech sheet doesn’t give the pin numbers for the defrost timer but it appears that in cooling mode, the defrost timer gets it power through the defrost heater and the defrost thermostat (supplier example only to show location and possible cost). See the Steps to enter electronic defrost control test mode (if applicable) (in the middle of the tech sheet) to check if the defrost thermostat opens and closes. Here’s a video that may help with testing the defrost thermostat. If the defrost thermostat is faulty search for WPW10225581 to get results for suppliers that suit you. Hopefully this is of some help. Update (02/21/2022) @Ikaros Uranus In defrost mode, is the heater actually getting warm? Is the evaporator fan working in cooling mode? In cooling mode check for voltage on timer terminal 2 (pink). If no good check on the defrost thermostat. If still no good check on the heater. Here’s an image how I think that it works. In cooling mode the red arrows show the path of the current to operate the timer. I think that the heater won’t get warm because there is not enough current for it but is enough for the timer. When the timer operates after 8 hours to start the defrost, the heater is turned on because the timer contacts have operated bypassing the timer motor (green arrow through heater). However there is also still a voltage coming from the evap fan circuit (see green arrow through the evap fan which goes through the timer motor) which should keep the timer working but maybe not the evap fan. After 21 minutes the timer contacts release and turn off the heater
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Hi: I just went through the same thing that you describe and spent a lot of time trying to find out why my evaporator would freeze every week. Changed the defrost time and it would advance occasionally and was very erratic. Checked the heating element it was fine. Advanced the defrost timer and it would kick into defrost. Finally I decided to change the defrost thermostat. Did a continuity test at room temperature and it did not register. I heard that sometimes even when there was not visual defects it could still be bad. I decided to change it and when I cut the leads off to put the new one in I noticed one of the copper wire was black and corroded when striped. I changed the defrost thermostat and now it seems to be working fine. I hope this helps you and I know how frustrating it can be. When you have ice build up in the evaporator and it does not defrost it look at the following or change all items listed. Defrost timer,Defrost thermostat, defrost heater. In some units also the control board if the defrost timer is built in. My freezer refrigerator was a KitchenAid KSSC48FJB00.
