late reply sorry- we been camping...
the 2 fans i added- I think I got 6 for $15 on ebay- they are quite efficient I control with a switch
the previous owner added a fan kit, which you can just see behind my fans, the sensor you can see top right
i also have a small fan inside my fridge- I salvaged that out of an old vcr...the wiring for that uses the same hole in the back of the fridge as the drain hose from the tray under the cooling fins
this is a pleasure-way lexor- it seems that I have better fridge access than some other rv owners