Whirlpool ART 535/G thermostat mystery

[img][img][img]I’m on the island of Hoy, Orkney and have a wide range of engineering experience going back 55 years but cannot figure the issue here.

Whirlpool f/f freezes fine but fridge compartment doesn’t cool below 12C – (best just leave stuff outdoors – it keeps longer). The compressor runs for a few minutes, the freezer compartment gets cold, then the machine switches off. Cranking up the thermostat to maximum has no further effect.
To identify the suspect t/stat I removed the housing from the fridge wall and on a hunch restarted the machine with the probe inside the fridge compartment. Magic! the fridge section now cools to minus 1C on max and plus 3C on medium.

I replaced the probe down the tube where it should be and go back to square one -temp stabilises above 10 C in fridge section- pull it out -works OK.

What is happening here? Thanks.
8564 535 15000
50 0127 004074