If you have a Dometic refrigerator installed, chances are it already has a fan installed. In 2008 or 2009 (I can't remember which) Dometic started shipping all their 6 cuft and 8 cuft LP/110 refrigerators with fans. It seems that they were having problems with manufacturers installing refrigerators without fans in slides and they weren't cooling properly. So, Dometic's "fix" was to just start adding the cooling fan to all refrigerators shipped from the factory. Double check yours, if you have a red 16 gage wire leading from the "black box" up toward the cooling fins with a fuse holder about midway up, then you already have the fan.
I don't know when Norcold started shipping with fans, but you should have one already installed if yours is a Dometic.
FYI: since your refrigerator is installed with a roof vent, you really won't see any improved cooling until the outside ambient temperature goes over about 90*F. All of the Dometic refrigerators were installed without the fan until kitchen slides came along. Since about 1960 or so, they have worked well without fans (provided they have the roof vent). It was only after the designers started calling for refrigerators to be installed in slides and the sidewall vents were necessary that cooling fans were required. If you boondock a lot, you probably wouldn't want a fan operating anyway. It will deplete your battery faster (even though it's only a small drain on the battery, it is a drain and reduces dry camping time).
Check and see if you have one installed, it will only operate when the ambient temp is above a specific range as determined by the thermistor, so it probably won't turn on until sometime next summer, but you can see it mounted above the rear cooling fins if it's installed. Check for the red wire first, it's easier to see.
Here's hoping
Hank & Lynn
.. Gonna miss her ... looking for new 5r)
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