Broken speedometer in Citroën Xsara

Hello, first of all I wanted to introduce myself, I am Merce, and I have an XSara 2.0 HDI of September 2000, the truth that the car has gone well, until I do not know what speed I go.
That is why I wanted to make a query, I do not know what to do to fix it, they have changed the speed controller and we continue the same, which I have spent the money at all.
Can someone help me please? What can I do to solve the problem? Thank you very much to everyone.