How do you fix the speedometer in a 1987 pontiac firebird?

To fix the speedometer in a 1987 Pontiac Firebird, first check the speedometer cable for any damage or disconnection. If the cable is intact, inspect the speedometer head itself for issues. You may need to replace the speedometer cable or the speedometer unit if they are malfunctioning. Additionally, verify that the vehicle's gear ratio matches the speedometer's specifications for accurate readings.