Harmonic balancer maybe bad or is it worse?

ok so the belts on my car dont turn when the car is started when it is off i can easily move them by hand (97 geo prizm ) thier is no friction so im looking around the bottom pulley is wobbly i am assumeing that this is the crank shaft pulley/harmonic balancer so here is what im wondering do i just need a ned harmonic balancer or is the problem worse car starts just fine but the belts dont turn causing the car to overheat and the battery to die can any one give my some info on these parts or maybe what all is wrong a video would be awsome