Problem with my accounting

Hello good morning to all the members of this forum
I am writing to ask about a problem that I have in my Chevrolet Monza year 94.

I tell you that my accountkilometers does not function me understand my piola and still it does not work, I turn my piola with my fingers and it works for me the accountability but when connecting it to the monor it does not work for me, I do not know what it can be for that.

The most possible thing is that the gear of the box is spent.

I agree with Bari, disconnect the gut, raise a tire and turn to check the gear, now if the gear does not rotate you already have the answer but if the gear if it turns then connect the gut and turn the tire again is the gut is the gut that reveals, if the gut does not turn Czech the union of the gut with the gear and check the entire gut, also the tag. Tag with your accountkilometers, out there, the problem is, luck ...