W 250 Pickup L6-359 5.9L DSL (1989)
Speed Control Servo: Testing and Inspection
1. Turn ignition switch and speed control switch to the On position, then connect a voltmeter to read battery voltage with negative lead on chassis
ground.
2. Disconnect servo 4-way connector.
3. Test blue/red wire of the main harness 4-way connector for battery voltage. If no voltage is indicated, check for loose connections, brake switch
adjustment, or repair main harness for an open circuit.
4. Connect a jumper wire between the male and female terminals of the blue/red wire. The other three male terminals from the servo should show
battery voltage. If not, replace the servo.
5. Using an ohmmeter, connect one lead to a body ground. With the other lead, touch the black wire terminal in the 4-way connector of the main
harness. Ohmmeter should show continuity. If not, repair ground wire for an open circuit.
