Retired on social security can I fund an IRA

No.

You must have earned income (Wages or self employment) to be eligible to make IRA contributions, deductible or non deductible, Roth or Traditional. 

You can open and make contributions to a traditional IRA if:

• You (or, if you file a joint return, your spouse) received taxable compensation during the year, and
• You weren’t age 70½ by the end of the year.