Nanna, Welcome to the forum & welcome to 3way fridges!
I've seen many references to T (Tropical) rated fridges - even caravans sold in Townsville, Cairns do not have this rating. After I "modified" the one in my camper (by adding two fans to the back - the bottom one blew air up, the top one sucked the hot air out), I discovered the T rated units had a fan or two in the back.
Mine developed the same fault a yours on our way back from Iron Range (a birding hot spot on Cape York) - it was ok until we reached Cairns. The service agent in Townsville suggested I remove the fridge & bring it in. I discovered a few things in this exercise - the fridge was held in by four small wood screws; on getting it out of the camper, I had to invert it & probably fixed the problem; it cost me $90 to have it sitting on test on the agent's bench for a couple of weeks to receive the no-fault-found report. It did not miss a beat after that.
That remedy is not always possible - this was a small 90L fridge. Go through the other reports & if necessary take it for an appraisal at a van/fridge agent. Generally the fridges are reliable & can work in a variety of conditions - if in the sun, that side of the van should be shaded some how (shade cloth).
Some people replace them with 12v fridge-freezers but that often requires more heavy batteries & extra charging facilities. And they can develop faults too!
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Warren
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If you don't get it done today, there's always tomorrow!