Test B: Warning Indicator Is On With Engine Running, System Is Not Charging

1. Measure voltage between ground and generator terminal B+ (Black/Orange wire). See Fig 1. If battery voltage is present, go to next step. If battery voltage is not present, repair circuit between generator and battery. See WIRING DIAGRAMS .
2. Disconnect generator 3-pin harness connector. Measure voltage between ground and generator harness connector terminal "A" (Yellow/White wire). See Fig 2. If battery voltage is present, go to next step. If battery voltage is not present, repair circuit between generator harness connector and fuse No. 20 (20-amp) in battery junction box. If fuse is okay, generator and battery. See WIRING DIAGRAMS .
3. Turn ignition on. Measure voltage between ground and generator harness connector terminal "I" (Light Green/Red wire). If battery voltage is present, go to next step. If battery voltage is not present, repair circuit between generator and instrument cluster. See WIRING DIAGRAMS .
4. Start engine and run at 2000 RPM. Measure voltage between positive battery terminal and generator terminal B+ (Black/Orange wire). If voltage drop is .5 volt or more, repair circuit between generator and battery. See WIRING DIAGRAMS . If voltage drop is less than .5 volts, replace generator.

Fig 1: Identifying Generator Terminals

Courtesy of FORD MOTOR CO.

Fig 2: Identifying Generator Harness Connector Terminals

Courtesy of FORD MOTOR CO,