I was told a trailer can qualify as a second home as long as it has all the necessary equipment to live in it (kitchen, bath, beds etc). That is supposedly the wrinkle that would allow for the deduction. A RV loan can be setup as a mortgage and the interest becomes deductible.
WBCCI Life Member 5123, AIR 70341, 4CU, WD9EMC
TV - 2012 Dodge 2500 4x4 Cummins HO, automatic, Centramatics, Kelderman level ride airbag suspension, bed shell
2014 31' Classic model 30 twin beds, 50 amp service, 900 watt solar system, Centramatics, Dill TPMS, disc brakes, 16" tires & wheels