Hard to turn steering wheel..have plenty power steering fluid..what's wrong???

Most likely bad p/s pump

Belt , pump or rack(steering gear) has failed. TEST first and verify , BEFORE buying wrong part(s).

If you have parked your car recently and hit a parking block or curb a little harder than usual, it will sometimes cause air bubbles to form in the fluid or cause and air pocket in the lines or cylinder in a rack and pinion set-up. When this happens, the steering is hard just like when you have the engine turned off. If you can turn the wheels all the way from right to left and back again several times, it is supposed to bleed the air out of the system. Had this happen on a Dodge RAM truck and could not believe that is what it was, but finally got the air out of the system and it worked fine again.