Originally Posted by milltown
Firstly, what are you doing driving a car you can't steer?
Does it turn slightly in either direction and then feel like it's hitting something solid? If so it could just be the steering lock in the ignition barrel. You don't say which Alfa or how old it is.
If it is very hard to turn but turns with a lot of effort then it could be power steering failure. If you take a look under the bonnet it should be pretty obvious if the belt has come off the power steering pump. If the car has been squealing for a while the belt was probably slipping, which would accelerate the failure of the belt. I'm not familiar with Alfas so I'm not sure what else is run off that belt.
Best case scenario: a new/used ignition barrel or a new belt.
Worst case: New power steering pump or rack.
From your brief description I'd guess it's the ignition.
Thanks for your reply.
First of all, I wouldn't drive it if I know there is something wrong with steering wheel.
The car was fine when I started it, and after a while I felt something broken under the bonnet and all of a sudden the steering wheel is very hard to turn(but turns with a lot of effort). Based on your diagnose, I believe its to do with the Power Steering Belt. Will get it sorted tomorrow!
Thanks for your help.