Where is the fan code box, we took off the light casing off, now we are trying to find the code box on the fan

Pray tell my dear, what are you talking about? Are you talking about the furnace fan, the fan in you computer or the fan on your bicycle?
What is a fan code box?

What is a "Fan code box"? Ceiling fan? Motor number? May be anywhere, usually on the top of the fan motor if that is what you want.