AVION Travel Trailers

Found power issue! ( bad connection at fuse ) but still no furnace....where should i look for the obvious? Trailer had been sitting for 5 years....

Ok, so i thought my thermostat was dead.... nope. I have no power going at furnace. Meter checked all the 12v fuses, and they seem to be good. Can someone clue me in as to what i may be missing? ( like which fuse it is
, etc ) 1984 Avion 30P. Thank you