Fan and Radio Problems

My 2006 Nissan Sentra’s fan & radio sometimes will not work when I turn on the ignition.
I then turn off ignition & turn it back on, the fan & radio work.
The Nissan dealer could not replicate the problem and sent me home.
Any suggestions?

Which fan?

does everything but those two items work?

Is the car running, or are you just turning the ignition to on?

I actually start the engine (turn on the ignition) and I’m referring to the fan/ac inside vehicle.

Well it’s NOT a fuse…Could be a bad ground…or a problem with the ignition switch.