Fixed Westinghouse Refrigerator WR4300WB NOT DEFROSTING & COOLING

I've been trying to find out the problem on my refrigerator since last year when it stopped cooling and there was a layer of ice built up on the lower panel near the vegetable drawer.

I tried to unplug the refrigerator and waited for a couple of days or more (in winter) to let the ice melt and it would be back to normal for a few months before the problem reoccurred.

After researching on YouTube, I found out ways to test the refrigerator components as follows:

1. Unplug the refrigerator power.
2. Remove two screws from the bottom panel (on top of vegetable/fruit drawer).
3. Remove a round plastic plug on the panel with a flat screw driver in order to enable you to pull the whole panel out using a finger.
4. Unplug three plastic connectors (fan, thermostat defrost termination, defrost heating element).
5. While the refrigerator is still cold, use ohm meter to check the resistance of the three components while unplug and all should show the following normal resistance:
1. Fan: around 30 ohms.
2. Thermostat Defrost Termination: around 0 ohms.
3. Heating Element: around 290 ohms.

I found my thermostat resistance was infinity so I suspect it caused the heating element to never started so the ice never got defrosted hence the refrigerator stopped cooling.

I'm waiting on the part (1448818) from ebay to come next week. Hopefully that's the only faulty component. Can't wait to see if the problem goes away after replacing it. Will keep you posted after I've replaced it.

--- latest updates 9 November 2018 ---
After replacing the part, the refrigerator has been working well for more than 5 weeks now:)