Assisted address fault

Hello everyone:

I would like to guide me for the repair of the assisted address of my Audi A3 1900 TDI of the year 1999.
In the control panel I have the battery light on, but it works because it starts without problems, circle without problems but suddenly without prior notice, without assisted direction. I want you to guide me before putting it in a repairs workshop to see if I can make a mechanic myself or I have no choice but to scratch my pocket ....
Thanks to all in advance.
Matthew

If you run out of battery and without assisted direction, which is possible that it is happening is the damper pulley of the crankshaft is broken the rubber and does not drag the belt that is the one that moves the alternator (from there the light battery light) and when turning the direction you cannot drag the hydraulic pump pulley (from there you are left without assistance in direction) Chalk and when I turn direction see if the brand has "misaligned". The price of this pulley must walk over 80 euros or less, and you can change it yourself (they are 8 -year -old screws, I think. Do not loosen the central screw, it is not necessary to change the pulley. Greetings !!

Thanks Ismael53 for your prompt response.
On Monday I will get to work according to your instructions. In any case, I will write again if I could solve it or not.
Thanks again.
Greetings
happy holidays !!