Will is never past tense.

Will is present or past?

Will is used for the future, but also for the present. Many people consider will to be the present form (its past form is would), and like all present forms, it can be used to talk about the present or future.

Will in a past sentence?

“Will” implies the intent to do something in the future. I will go to the store. To make it past tense, you would say I went to the store. If you want to imply the desire to do something in the past, you could say “I intended on going to the store but I didn't” or “I intended on going to the store and I did so.”