have a 2010 turbo A4 diesel v6. for some reason the power steering is hard , checked the the lower universal joint on the steering shaft which they said could get dry and start to bind causeing a stiffness when turning,but that is in perfect condition, and i also checked the fluid level , and checked ALL the fuses , both on each side of the dash, and in the boot. no blown or missing ones. any ideas on what to check next ?