Hi @greengiant27 ,
When you say “thermostat” do you mean the defrost thermostat - part #32 liner parts diagram? If not there are plenty of videos on YouTube how to test a bi metal thermostat
Also have you checked that the compressor overload protector and start relay part #s 13 & 13A unit parts diagram are OK?
Hi @greengiant27 ,
Initially it may be safer to use an Ohmmeter to check for continuity in the wiring from the heater’s harness connection.
Disconnect the power from the fridge and then disconnect the heater from the wiring harness and test the wires that are coming to the heater, not the wires from the heater.
I cannot find a wiring diagram or a service manual for your model but here’s an image that has two circuits that show how it might be wired. I’ve drawn in arrow points where to connect the Ohmmeter. It tests the wiring path between the components and the supply
As I said it might be the same or similar to your model, but then again maybe not. Check what colours the wires are as that may also help to identify if it might be the wire you need to connect to with the meter. The Neutral wire should be white or grey. As for the others they are shown on the diagrams but they may be different in your model.
If either wiring diagram is not similar then you will have to connect the Voltmeter in place of the heater (or between the heater and earth with the heater still connected) and check.
Turn off the power and jam the meter leads in the heater harness plug connector so that you don’t have to be holding them and then turn on the power. Turn off the power before touching them again.
Unfortunately, I don’t know how to force a defrost cycle in your model so I don’t know how long you’d have to wait before it enters the defrost cycle so that you can test
(click on image to enlarge for better viewing)
I realize that you said that you replaced the defrost thermostat but here’s a video that shows how to test if one is OK and it also has good information about how to find out at what temperature they release and then re-operate, as the defrost thermostat does play a big part in the heater operate circuit.
In the circuit on the left it actually closes and opens the heater circuit so the timer can still cause a defrost cycle to commence and cease but there may not be a heater circuit. In the one on the right it opens the timer and the heater circuit so if the timer has no power then there will never be a defrost cycle.