You can deduct interest you pay on a loan secured by your main home (where you ordinarily live most of the time) and a second home which includes a motorhome.

1. Click the FEDERAL on the left tab
2. Select DEDUCTIONS & CREDITS at the top of the screen
3. Select show all tax breaks
4. Choose YOUR HOME and select Show more
5. Click the START button on the line in this sub-group that is labeled MORTGAGE INTEREST, REFINANCING & INSURANCE 

https://ttlc.intuit.com/replies/3301694