I was right about this. Your great grandfather was Thomas Oliver Ault b. 24 Jan 1880, Indiana, d. 20 Jul 1933 Council Bluffs, IA, m. Hyla Louvena Dearinger 16 Apr 1902. Thomas was the son of John Ault & Sarah Ann Keeley. I found them on the 1895 Iowa State Census, Burlington, Des Moines Co. John Ault age 54 b. Ohio, Sarah Ault age 50 b. Indiana, Nettie Ault age 17 b. Indiana, Thomas age 15, b. Indiana, Nellie Ault age 12 b. Indiana.
Then if you will go to the Ancestry Family Trees and do a search for Thomas with parents John Ault & Sarah Ann Keeley, you will get the whole family and the tie in you need. Look for the data posted by Ann Grubb -The Gilchrist - O'Dell Connection