Speedo works, odometer doesn't

I have a '91 LTD Crown Vic. The speedometer works, but the mechanical odometer and trip counter doesn't.

I've concluded that the speedo is electronic, since it still works. Is the odometer on these cars driver by a cable from the tranny, or is it electronic, also?

Rob

This is all done electronically there actually motors on the back that receive signal from the speed sensor on the side of the tranny and turns the odometer. Since the speedo works. I think the problem is in the odometer part in the dash.