I just bought a beater car. Its a 89 chevy caprice. And the speedometer is ticking me off. The only way it works is to get it going in drive and then put it in neutral while still rolling and the speedometer will jump up to the speed that I am going. But as soon as I put it back in drive It shoots back to 0. Im stumped I moved the speedometer cable but still does the same. Does anyone have any ideas?

Chris