Test B: Warning Indicator Is On With Engine Running, System Does Not Charge
WARNING: This page is about a different car, the 2004 Ford Pickup, 2004 Ford F550 Super Duty, 2004 Ford F450 Super Duty, and 2004 Ford Excursion. However, it is still accessible from the selected car via links, so may be relevant.
- Check Generator B+ Circuit (Yellow/White Wire)
Measure voltage between ground and generator terminal B+ (Red wire). See Figure. Is the voltage equal to battery voltage? If yes, go to next step. If no, repair circuit between generator and battery. See WIRING DIAGRAMS . - Check "A" Circuit (Orange/Light Blue Wire)
Disconnect generator 3-pin connector. Measure voltage between ground and generator harness connector terminal No. 3 (Orange/Light Blue wire). See Fig 1. Is the voltage equal to battery voltage? If yes, go to next step. If no, repair circuit between generator and battery. See WIRING DIAGRAMS . - Check "I" Circuit (Light Green/Red Wire) For An Open
Turn ignition on. Measure the voltage between ground and generator harness connector terminal No. 1 (Light Green/Red wire). See Fig 1. Is the voltage equal to battery voltage? If yes, go to next step. If no, repair Light Green/Red wire between generator and instrument cluster. See WIRING DIAGRAMS . - Check For Voltage Drop In B+ Circuit (Yellow/White Wire)
Turn ignition off. Connect generator 3-pin connector. Start engine and let idle. Turn headlights on. Turn rear defogger on. Turn blower motor to high speed. Increase engine speed to 2000 RPM. Measure voltage drop between generator terminal B+ (Red wire) and positive battery terminal. See Figure. Is the voltage drop less than 0.5 volt? If yes, install a new generator. See GENERATOR under REMOVAL & INSTALLATION. If no, repair high resistance condition in Red wire between generator and Gray fusible link. See WIRING DIAGRAMS .