If you have power steering assist then it is going to be hard to move if the engine isn't running. If you don't have power steering then check as Mark suggested by pulling out the clevis pin that connects the steering cable to the steering lever and see which is easier to move, the drive or just the cable. Most of the time the problem is where the steering cable goes through the guide tube behind the engine, the grease gets all dried up causing it to bind. You may have to remove the cable from the tube, clean it out and reinstall it with fresh grease.