TT will not let me enter a qualifying 1098 for my timeshare. What are the exact steps I must take in the software to enter this?

Your main home and second home qualify to deduct mortgage interest while all properties can deduct property tax. If your timeshare is your second home, mark it as second home. If you already have 2 homes, then the mortgage interest would not be deductible, just the property tax.

Here are the steps:

1. To add another 1098, select add a lender, 
2. enter lender name
3. continue
4. Second home
5. continue
6. Any of these situations apply? - probably none of the above for you
7. Continue
8. box 1 Mortgage interest - enter amount
9. box 3 mortgage origination date- enter yours
10. Property tax paid - enter amount
11. continue
12. Is this loan secured by a property of yours
13. YES
14. continue
15. points paid  - assume no points, make your selection
16. continue
17. most recent loan, select yes
18. continue
19. details about loan, select neither of these
20. continue
21. money exclusively on home - select yes
22. continue
23.  
24. You have successfully entered your information!