12V fridge thermistor issues.

[loanrangie]

I have a stirling 40l fridge that was showing 41C on the display even though it was cooling, no probs i thought usual symptoms of a faulty thermistor.
I had a spare thermistor that i bought when i fixed my 50l with the same problem, fitted said thermistor and compressor runs but display was showing -08 which it definitely wasnt in the cabinet.
Got out the multiple and it showed as 16k at about 20c approx, should be 10k at 25c. So called into Jaycar and got a couple of 10k NTC thermistors and soldered one onto the original cable, heat shrink tube and refitted.
Still showing negative temps on the display, if i leave the thermistor hanging out it reads roughly the approx cabinet temp ?

[loanrangie]

With the thermistor hangout out in ambient the display is showing 0-1 which i assume should be ambient at 24c ? I've swapped over to 12V to see if there is any difference.

[loanrangie]

Removed a sticker off the base to find an access hole for the thermistor, dug out the insulation and found a metal tube where it sits which looked a little rusty.
Made a new hole and used thermal glue to mount the new thermistor on a clean section of the base, some aluminium tape and I'll stuff some Eva yoga mat in to fill the void.https://uploads.tapatalk-cdn.com/20231223/73777812f1345157e266d165aee27042.jpghttps://uploads.tapatalk-cdn.com/20231223/83504bf53c55d4f3ba3f8063427d59e4.jpghttps://uploads.tapatalk-cdn.com/20231223/5c5f696e004539038634cb1c9ab44142.jpg

[loanrangie]

So I discovered that this particular fridge uses a 2k thermistor which jaycar don't stock so I soldered 2 x 1k in series and display now shows closer to the set temperature.
I ordered a few 2k off AliExpress for spares, also got a new insulated cover from jaycar on clearance for $13.
I bought this as a gift for my nephew who is going away camping this week so got it fixed just in time.