When I localized the problem to the sensor, I posted the model # & the problem to the Trailer Life tech problem forum. There's an RV fridge tech w/a few decades of experience that chimed back something to the effect of "look to the right & just be low the fins for a 1/8" dimple in the plastic liner of the fridge; drill a 1/4" hole there for fishing the new thermistor wire to the back of the fridge (that's what the dimple is there for)." Worked like a charm. The original wire pair was molded into the back insulation as the method of routing; couldn't back-pull it to repull the new one. Dometic probably has a similar process for the newer zig-zag fridges. Once the hole was drilled, you could fish a second, third,... thermistor as needed.
Baja-tested '08 2-slide 36'
Alpine: The Ultimate DIY'er Project