Pickup & 4Runner - Carbureted

Jack up and support one rear wheel off ground. Release parking brake. Place shift lever in Neutral. On 4WD models, ensure transfer case lever is in "2H" position.
Unplug wiring connector from computer. Computer is located at left kick panel. Test "ON-OFF" cycles of speed sensor using an ohmmeter. See Fig 1. Insert a 10-ohm resistor in series with positive ohmmeter lead and insert lead in rear of connector. Connect negative terminal to ground.
Slowly turn wheel, checking to see that ohmmeter needle deflects consistently. If ohmmeter needle does not deflect, check that sensor leads are firmly connected to rear of speedometer. If connections are okay, replace speedometer assembly.

Fig 1: Testing Speed Sensor (Carbureted Pickup & 4Runner) Insert positive lead into rear of connector.