The first thermostat, 10442411, I got from you tested 56K Ohms both cold and warm. The replacement tests 56K or 55K Ohms, (using three different meters), when warm, and 0 Ohms when cold. I expected that it should have tested "Open" rather than 56K Ohms, when warm. I need to know if this is correct, before I install it. By the way, the heater tests 34.7 Ohms, is this as it should be?
Answer Hello Mickey,
The open resistance is a bit beside the point. You see, when it opens, it is doing so because the evaporator compartment has reached 50°F or so and if the heater didn't cool down at this point, food would defrost and cause spoilage. Many defrost thermostats open to a high resistance to prevent the water from the melting frost from freezing on its' way to the defrost drain. It should read 0O resistance when cold so the heater will receive full voltage for the defrost cycle to proceed normally. The heating element resistance is normal also.