Does Enhance Ability Work On Saving Throws?
No. Whilst the spell does grant advantage on checks, it doesn't for saving throws. An often overlooked rule, many mistakenly think of saving throws as a type of check. They indeed have a lot of things in common: rolling a d20, adding modifiers and attempting to beat a difficulty class. Unfortunately, however, they are not the same thing, and this spell will do nothing to help you take half damage from a fireball or resist the charms of a succubus.