Originally, one had to physically start the motor of a car or plane . This meant sticking a handle (a crank) in the front and turning it until the motor could run my itself. So if you turn someone's crank, you get them "started" (excited).

Yeh it is like turning her on. It could also mean what interests her.

I guess maybe it's an idiom (turn your crank) which means: inspire on interest you. ex: "seeing the marching soldiers turns his crank. He's dreaming of becoming a soldier someday." :)

This that it what very to be pleasant. That from what the person beside himself. Something very favourite and raising