Test F
PINPOINT TEST F: THE CHARGING SYSTEM WARNING INDICATOR FLICKERS OR IS INTERMITTENTTest F1-F3:
Normal Operation
With the engine running, the charging system warning indicator is off. The sense A circuit 35 (OG/LB) to the generator field coil is 13-15 volts. The S (stator) circuit (internal to the generator on all 4.6L vehicles and only on 4.0L vehicles built to December 8, 2003; but an external circuit 4 [WH/BK] on 4.0L vehicles built from December 8, 2003) is used to feed back a voltage signal from the generator to the voltage regulator. This voltage feedback signal (typically half the battery voltage) is used by the regulator to provide a signal to the PCM which in turn provides a signal over the CAN communication link to the instrument cluster to turn off the charging system warning indicator. The I (ignition) circuit 904 (LG/RD) is used to turn on the voltage regulator. This circuit will be 6-8 volts (C102a connected) with the key in the ON position and the engine not running. Once the engine is started, the I circuit will measure 8-10 volts (C102a connected). The battery positive output (B+) circuit 38 (BK/OG) is the generator output supplied to the battery and electrical system.
Possible Causes
- battery junction box (BJB) fuse links 290A (GY 12 GA), 290 (GY 12 GA) or 292 (BN 18 GA) intermittently open
- external stator circuit 4 (WH/BK) (if equipped) open or high resistance
- generator connections
- generator