My defrost thermostat is closed at room temperature I assume that show it is good…right or wrong?
That is correct, they open above 100 degrees. If it is bulged, or you think it might be bad, replace it, they are cheap enough and considering age, should be replaced to prevent future failure.
thermostat is closed at room temperature I assume that show it is good…right or wrong?
Half right.
The other half is as richappy said.
It must open above 100.