Smart RV products / Frig Fix

Mine came factory equipped, from Dometic, with a single thermostatically controlled fan, probably 4" fan. Mounted at the top blowing out the external vent. I thought it looked rather useless with no baffle or anything, but it actually moves enough air out that even with the fridge in a slide it cooled pretty well - and this has been a very hot summer for this area. It's pretty much always on, use a manual switch for your installation and likely not much different.
The internal fans are likely even more important, I made mine from 3 1" USB (so 5 volts) fans from a laptop. They are mounted right on top of the fins and powered from the light wires, no issues with interference with an overstocked fridge like the battery powered units that sit on the self but I've heard lots of people say they work fine too.

I installed 2 fans to move the hot air outside, improved the reefer a lot.
Outside ambient temp has an effect on the cooling. I also installed a small thermostat in line with the 12V computer fans so at a cooler outside temp The fans do not run I also installed a switch inside to turn them off if the reefer is shut down.

A fan inside your fridge is the least effective (but cheapest) from of getting better cooling. If your fridge is not cooling you need to find out the "actual" reason that you have a problem. Too much stuff inside preventing normal air circulation might be one. The shelving is open for a very specific reason! Many RV manufacturers did not properly install the fridge and the associated venting system. If there is too much air space behind the fridge, the fridge will not cool properly. That sounds contradictory but the reality is that the absorption fridge is not like any household fridge you might be familiar with. There are very specific parameters that must be met for the unit to work properly. You should list the fridge you have, the manufacturer and whether it is installed in a slide out or not. I suspect there is/was someone dealing with the same problems you are seeing.