Beko f/freezer:testing thermal fuse

[Deluks]

Model CXFG1552W

This unit crapped out recently. First to go was the freezer compartment, all the food was soft, fan was running.
Couple of days later the fridge starts running warm.

Not frost in freezer compartment, and I've tried leaving it turned off for a few days and trying it again, without luck.

Trying to troubleshoot using t'internet.
Found the thermal fuse, this unit in the picture.

Got the multimeter out, set to 20k, I'm supposed to test across the terminals, and it should read zero if it's working. But which two terminals? The components on all the YouTube vids seem to have two terminals, mine has 4.

I'm not what wire does what, can anyone enlighten me please? (Preferably in idiot terms as electronics is not my strong point)

 

[fourtytwo]

I had an Indesit FF with a problem and also found on of these amongst the coils in the freezer, it also had 4 wires and as far as I remember they were all RED! In any case there are two thermal fuses in there to make it fail safe in case one fails to open and they are in series with the defrost heater (thin pipe also buried in freezer coils). You should find a short circuit between a pair of wires and another between the other pair but no connection between the shorted pairs. Mine was open causing the freezer to freeze up.
TBH in your case it sounds more like the compressor is either not working (thermostat failure) or the refrigerant circuit is broken, the coils at the back of the fridge should get warm and those inside the compartments cold. Is the compressor running, can you hear it or feel it vibrating ?