Test H: Speed Control Amplifier Does Not Respond To NGS Tester
- Turn ignition off. Disconnect speed control amplifier 10-pin connector located in left rear of engine compartment. Inspect connector for loose, damaged or corroded terminals. Repair connector as necessary and retest system for normal operation. If connector is okay, reconnect connector. Turn ignition on. Perform data link diagnostic procedure. See DATA LINK DIAGNOSTIC TEST under COMMUNICATION NETWORK DIAGNOSTICS. If NGS tester indicates NGSC: NO RESPONSE ON CKT 914 (BUS +), go to next step. If NGS tester does not indicate NGSC: NO RESPONSE ON CKT 914 (BUS +), go to step 4).
- Turn ignition off. Disconnect NGS tester. Disconnect speed control amplifier 10-pin connector. Using an ohmmeter, measure resistance of Tan/Orange wire between terminal No. 1 at speed control amplifier connector and terminal No. 2 at Data Link Connector (DLC). See Figure and Fig 1. If resistance is less than 5 ohms, replace speed control amplifier and retest system for normal operation. If resistance is 5 ohms or more, go to next step.
- Disconnect 76-pin connector C201 located behind left side of instrument panel. See Figure. Inspect connector for loose, damaged or corroded terminals. Repair connector as necessary and retest system for normal operation. If connector is okay, measure resistance of Tan/Orange wire between terminal No. 59 at connector C201 and terminal No. 2 at DLC. See Figure and Figure. If resistance is less than 5 ohms, repair open in Tan/Orange wire between speed control amplifier connector and connector C201. Retest system for normal operation. If resistance is 5 ohms or more, repair open in Tan/Orange wire between connector C201 and DLC. Retest system for normal operation.
- Turn ignition off. Disconnect NGS tester. Measure resistance of Pink/Light Blue wire between terminal No. 2 at speed control amplifier connector and terminal No. 10 at DLC. See Figure and Fig 1. If resistance is less than 5 ohms, replace speed control amplifier and retest system for normal operation. If resistance is 5 ohms or more, go to next step.
- Disconnect 76-pin connector C201 located behind left side of instrument panel. See Figure. Inspect connector for loose, damaged or corroded terminals. Repair connector as necessary and retest system for normal operation. If connector is okay, measure resistance of Pink/Light Blue wire between terminal No. 60 at connector C201 and terminal No. 10 at DLC. See Figure and Figure. If resistance is less than 5 ohms, repair open in Pink/Light Blue wire between speed control amplifier connector and connector C201. Retest system for normal operation. If resistance is 5 ohms or more, repair open in Pink/Light Blue wire between connector C201 and DLC. Retest system for normal operation.
Courtesy of FORD MOTOR CO.