Whirlpool model ED5LHAXWQ00 defroster not defrosting

Refrigerator & Freezer Repair
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1

its a side by side freezer/fridge

so both the fridge wasn’t cooling down and the freezer items started to defrost.

there was a lot of ice visible on the freezer inside panel. so i checked the following:

  1. thermostat..it was closed (showed continuity) when it was frozen and it showed open (no continuity) when at room temperature. means = thermostat is good
  2. checked heater wire: shows a resistance of 23.7 ohms…i think this is good, right?

then i removed the thermostat, and joined the wires together to bypass the thermostat to ensure the loop is closed, then:
3) voltage at the wires for the heater measure = 6.7volts
4) i had a spare defrost control board, put it in there and measured the voltage at the wires, replaced it and the voltage still measure 6.7 volts at the heater wire.

question:

  1. what voltage should i be reading at the wires at the heater…120v AC, right?
  2. by connecting the wires for the thermostat, i have closed the loop right? so the board should be sending voltage for the heater wire to turn on, right?
  3. what is wrong?
  4. how do i know if the defrost control board is bad? at the white and black terminals on the the defrost control board, it measures 120 volt
2

here is how the issue was fixed: the following is what was suggested to me on another forum,

-need to put the refrigerator into forced defrost mode first.
-there was someone from another site kind enough to share the instruction…in the link below.
-do this will tell me if the system is working:

  1. if it heated…this means that the heater is working, defrost control board is working and means that the bi-metal thermostat on the coil might not be working…need to check it again.

Check the bi-metal.
It should be closed (0 ohms) when frozen. But also should be 56,000 ohms when at room temperature.
It has to have the 56Kohms in order for the defrost board to work correctly.

  1. if not, then:
    a)i need to measure the voltage across the white and pink terminal on the defrost control board to ensure it reads 120v…if not, then the control board is no good.

here is the doc for the method of forcing the fridge into defrost mode: