To my surprise, I received previously ordered 7" square mount fan yesterday afternoon. With parts in hand, I created the rough opening and secured (glued and screwed) its outer edges - to make better mounting surface.
Factory access hole / removable panel:
Rough "round" opening:
Fan's "rough / dry" fit (with no inner cab cover):
- Buy / create inner side protective cover. I'm thinking rabbit cage galvanized wire mesh. We'll see what local stores sell. Being under the middle seat, the inside cover won't be seen. It's more of a safety cover need.
- Install 12V / 14 gauge wiring with simple 5 Amp inline fuse. Will try "temp" off/on toggle switch for now. I will "wire in" a lighted LED rocker switch on its dash panel later. Thus, easily turn off / on when needed.
- Secure the fan's square assembly using simple 4 x screws and flat washers. Something simple - so it can be easily removed every spring (to replace its inner hole Engine oil filter).
Note: This is a 12V 4.5A (estimated max 325 CFM) push or pull 7" Radiator fan - installed in a pull position. Hoping this mid size 350 CFM RAD fan is perfect CFM size (for my climate's region) and 380 dB sound level.
More future updates to share - if you are thinking of doing the same / similar DIY upgrade on your Prowler.