My air conditioner fan in front console & back ac will randomly not come on.

What is your question?

This has occurred twice on initial start up. On the first fail, the next day or two later, the ac fan started with the engine with no cooling issues. No lights failed &/or no alerts on the console. Engine sounds as if pulling energy when ac turned on. Ac setting (fan speed or temperature) adjust without problem but NO FAN AIR out of vents. What could it be? Thanks:)