[sc0ttr0sari0]

Every few weeks, refrigerator and freezer gets warm. The fan in freezer works okay. I've noticed after removing the rear panel that the evaporator coil is iced-up. After melting the with a hairdryer, refrigertor and freezer seems to operate normally for a few weeks. I got my dvom ready, just need test procedures. Thank you.

[denman]

Here are your parts
Replacement parts for Maytag M1TXEMMWW03 REFRIGERATOR | AppliancePartsPros.com

See the attachment for the tech sheet.


First remove the evaporator cover in the freezer so you can see the coils.
Do not let them de-ice.

If yes.
Manually force a defrost cycle, see the tech sheet. When the fans and compressor turn off, you are in a defrost cycle.

Now check the defrost heater to see if it is on.
Be careful you do not want to burn your fingers.
If the heater is on then the defrost board (Item 4 in Section 3) needs replacing, re: it is never getting into a defrost cycle.

If not on.
Unplug the unit.
Remove the wire for one side of the heating element (Item 4 in Section 4) from the wiring and measure it for continuity, usually around 20 ohms or so.

If the heater is OK
Remove one wire to the defrost thermostat (Item 25 in Section 3) and measure it, should be 0 ohms when frozen. Or you could use a jumper across the test terminals. Note that it opens just above freezing so must be frozen to check it. Also inspect it, if it is bulged at all replace it even if it measures OK.

If both the above are OK then odds are the defrost board is toast.
Best way to test this is a live test to see if you have 120 volts across the heater/defrost thermostat combo.

[fix4dyer]

I've seen that the defrost heater shoud be about 20 ohms. I'm reading 40 ohms on my heater, does this mean I need a new heater?

[denman]

No your heater is OK.

If you take a look at the tech sheet I attached to the original post the spec is 42 to 30 ohms.