Vauxhall zafira club 2003 model steering column stiff to steer (follow on)?

We have now taken the car to a Vauxhall dealership after it was discovered that a 80amp fuse had blown near the engine and when they replaced it with a new 80amp fuse it blew as soon as the ignition was turned on. We were advised to take the car to reg vardy and they insist that the car needs a new power steering motor at a cost of around £600 and apparently the leak looks like something has been topped up and just drips from that. The car is running a 8000w amp and a 3000w amp and a 80w head unit but the amps nor the new stereo were running when the new fuse blew at the first garage.