Camper, I moved your thread to the electrical section because I think you'll get more help here rather than in the "forum suggestions" section.
Are you possibly talking about the AC/DC converter that's in the HiLo to change shore power to 12V DC and also charge the batteries? An "inverter" changes 12V DC to 120V AC power, and HiLo rarely put those in trailers, although there were a few that had them.
What kind of cooling fan did you install, was it an identical replacement for the one that you took out?
Hi-Lo 1707T - Tire Minder TPMS on Tow Vehicle and Trailer, 300W Solar Battery Charger, Equal-i-zer WDH, Progressive Dynamics Converter
2014 F150 Platinum 4x4 3.5L EcoBoost SCrew