Hi and help please with 2001 Punto

[Dave7591]

Hi looks a great forum this with some good advice available. Recently bought a 2001 1.2 8v Punto and was running great until yesterday when the power steering light came on on the dash and steering now like concrete. (City button non functional now). After reading other posts I have checked battery and showing 12.6V so appears to be ok. Can anybody suggest any other possibilities please? Cheers Dave

 

[Dave7591]

Just to add to the above.
Have now tested the large blue fuse in the engine fuse box and also the fuses in the box under the steering wheel. All ok.
However
If I turn the key to MAR the warning light goes out as it should and can switch into city mode BUT as soon as I start the engine the warning light comes back on and no power steering.

Makes me think maybe it is a battery problem anybody else agree please