Speed Continuously Changes Up and Down

1. Check to ensure proper operation of actuator linkage. If found satisfactory, proceed to step 2. If not found satisfactory, service or replace actuator linkage.
2. Check operation of speedometer cable for proper routing and ensure no sharp bends or binding exists. If found satisfactory, proceed to step 3. If not found satisfactory, service or replace speedometer cable.
3. Check to ensure proper operation of sensor. If found satisfactory, proceed to step 4. If not found satisfactory, replace sensor.
4. Perform tests on speed sensor. If found satisfactory, proceed to step 5. If not found satisfactory, replace speed sensor.
5. Check to ensure proper operation of vacuum dump valve. If found satisfactory, proceed to step 6. If not found satisfactory, service or replace as necessary.
6. Perform tests on amplifier. If found satisfactory, proceed to step 7. If not found satisfactory, replace amplifier.
7. Examine all connectors to ensure proper contacts.