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Test A: Speed Control Is Inoperative

  1. Check For Voltage To Speed Control Servo/Actuator  - Disconnect speed control servo/actuator connector C136 (located near master cylinder). Turn ignition on. Using a voltmeter, check voltage between speed control servo/actuator connector C136 terminals No. 7 and 10. See Fig 1 . If battery voltage exists, go to step 4). If battery voltage does not exist, go to next step.
  2. Check Ignition Circuit  - Turn ignition switch to RUN position. Using a voltmeter, check voltage between ground and speed control servo/actuator connector C136 terminal No. 7. See Fig 1 . If battery voltage exists, go to next step. If battery voltage does not exist, check instrument panel fuse No. 6 (15-amp) and replace as necessary. If fuse is okay, repair open power circuit. If fuse repeatedly blows check circuit for short to ground and repair as necessary. Retest system operation.
  3. Check Speed Control Servo/Actuator Ground Circuit  - Using an ohmmeter, check resistance between ground and speed control servo/actuator connector C136 terminal No. 10. See Fig 1 . If resistance is less than 5 ohms, repeat step 1). If resistance is 5 ohms or more, repair open in Pink/Orange wire between speed control servo/actuator and ground. Retest system operation.
  4. Check Deactivator Switch Circuit  - With brake pedal released, check voltage between speed control servo/actuator connector C136 terminals No. 9 and 10. See Fig 1 . If battery voltage exists, go to step 7). If battery voltage does not exist, go to next step.
  5. Check For Voltage To Deactivator Switch  - Disconnect speed control deactivator switch connector C261 (located on clutch pedal support). Using a voltmeter, check voltage between ground and speed control deactivator switch connector C261 Light Green/Red wire terminal. If battery voltage exists, go to next step. If battery voltage does not exist, check instrument panel fuse No. 9 (15-amp) and replace as necessary. Check for open Light Green/Red wire. Repair as necessary. Retest system operation.
  6. Check Orange Wire  - Using an ohmmeter, check resistance in Orange wire between speed control servo/actuator connector C136 terminal No. 9 and deactivator switch connector C261. See Fig 1 . If resistance is less than one ohm, replace deactivator switch and retest system operation. If resistance is one ohm or more, repair open in Orange wire between deactivator switch and speed control servo/actuator. Retest system operation.
  7. Check Brake Pedal Position (BPP) Switch (With Brake Pedal Released)  - With brake pedal released, check voltage between speed control servo/actuator connector C136 terminals No. 4 and 10. See Fig 1 . If battery voltage exists, replace BPP switch or repair Red/Light Green or Light Green wire between BPP switch and speed control servo/actuator. Retest system operation. If battery voltage does not exist, go to next step.
  8. Check Brake Pedal Position (BPP) Switch (With Brake Pedal Applied)  - With brake pedal applied, check voltage between speed control servo/actuator connector C136 terminals No. 4 and 10. If battery voltage exists, go to step 12). If battery voltage does not exist, go to next step.
  9. Check Brake Pedal Position (BPP) Switch Resistance  - Disconnect BPP switch connector C242 (located on top of brake pedal support). Using an ohmmeter, check resistance between BPP switch terminals while pressing brake pedal. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, replace BPP switch and retest system operation.
  10. Check For Voltage To Brake Pedal Position (BPP) Switch  - Using a voltmeter, check voltage between ground and BPP switch connector C242 Light Green/Red wire terminal. If battery voltage exists, go to next step. If battery voltage does not exist, check instrument panel fuse No. 9 (15-amp) and replace as necessary. Check for open Light Green/Red wire. Repair as necessary. Retest system operation.
  11. Check Red/Light Green Wire & Light Green Wire  - Using an ohmmeter, check resistance in Red/Light Green wire and Light Green wire between speed control servo/actuator connector C136 terminal No. 4 and BPP switch connector C242. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Red/Light Green wire or Light Green wire between BPP switch and speed control servo/actuator. Retest system operation.
  12. Check Clutch Pedal Position (CPP) Switch Resistance  - Disconnect CPP switch connector C260 (located on top of clutch pedal support). Using an ohmmeter, check resistance between CPP switch terminals while pressing clutch pedal. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, replace CPP switch and retest system operation.
  13. Check For Stuck Speed Control Switch  - Without pressing any speed control switches, check voltage between speed control servo/actuator connector C136 terminals No. 5 and 10. See Fig 1 . If battery voltage exists, replace speed control switch assembly. If battery voltage does not exist, go to next step.
  14. Check ON Switch Operation  - While pressing speed control ON switch, check voltage between speed control servo/actuator connector C136 terminals No. 5 and 10. See Fig 1 . If battery voltage exists, go to step 18). If battery voltage does not exist, go to next step.
  15. Check For Power To Air Bag Sliding Contact  - Disable air bag system. See appropriate AIR BAG RESTRAINT SYSTEM article. Disconnect air bag sliding contact connector C233 (located at base of steering column). Using a voltmeter, check voltage between ground and air bag sliding contact connector C233 (female side) Yellow/Light Green wire terminal. If battery voltage exists, go to next step. If battery voltage does not exist, check engine compartment fuse block HORN fuse No. 5 (20-amp) and replace as necessary. Check for open Yellow/Light Blue wire. Repair as necessary. Check horn relay and Yellow/Light Green wire. Repair as necessary. Retest system operation.
  16. Check Air Bag Sliding Contact  - Disable air bag system. See appropriate AIR BAG RESTRAINT SYSTEM article. Remove drivers-side air bag module. Remove speed control switch assembly. Using an ohmmeter, check resistance of all wires between air bag sliding contact connector C233 and speed control switch assembly connector. See WIRING DIAGRAMS. If resistance is not .25-.50 ohm, replace air bag sliding contact and retest system operation. If each resistance reading is .25-.50 ohm, go to next step.
  17. Check Circuits Between Air Bag Sliding Contact & Speed Control Servo/Actuator  - Disconnect speed control servo/actuator connector C136 (located near master cylinder). Using an ohmmeter, check resistance in Light Blue/Black wire and Dark Green/Orange wire between speed control servo/actuator connector C136 and air bag sliding contact connector C233. See WIRING DIAGRAMS. If resistance is 5 ohms or more, repair open in Light Blue/Black or Dark Green/Orange wire(s). Retest system operation. If resistance is less than 5 ohms, replace speed control switch assembly and retest system operation.
  18. Check For Stuck Switch  - Without pressing any speed control switches, check resistance between speed control servo/actuator connector C136 terminals No. 5 and 6. See Fig 1 . If resistance is more than 3 k/ohms, go to next step. If resistance is 3 k/ohms or less, replace speed control switch assembly and retest system operation.
  19. Check SET/ACCEL Switch Operation  - While pressing SET/ACCEL speed control switch, check resistance between speed control servo/actuator connector C136 terminals No. 5 and 6. See Fig 1 . If resistance is 646-714 ohms, go to next step. If resistance is not 646-714 ohms, replace speed control switch assembly and retest system operation.
  20. Check Vehicle Speed Sensor (VSS) Circuit  - Using an ohmmeter, check resistance between speed control servo/actuator connector C136 terminals No. 3 and 10. See Fig 1 . If resistance is not 200-300 ohms, go to next step. If resistance is 200-300 ohms, go to step 22).
  21. Check Vehicle Speed Sensor (VSS)  - Disconect VSS connector C129 (located on left rear of transmission). Using an ohmmeter, check resistance between VSS terminals. If resistance is 200-300 ohms, check for open or short in Gray/Black or Pink/Orange wire(s). Repair as necessary and retest system operation. If resistance is not 200-300 ohms, replace VSS and retest system operation.
  22. Check For Broken Or Binding Servo/Actuator Cable  - Remove speed control servo/actuator cable from speed control servo/actuator. Check for broken or binding cable by pulling on cable ball slug to ensure throttle moves freely. Replace cable as necessary and retest system operation. If cable is okay, replace speed control servo/actuator and retest system operation.
Fig 1: Identifying Servo/Actuator Connector C136 Terminals
G96B29331Courtesy of FORD MOTOR CO.
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