Cherokee 4WD L6-242 4.0L VIN S MFI (1992)
Generator: Description and Operation
Alternator Field Output
PURPOSE
The engine controller continuously monitors battery voltage inputs, and since battery voltage always fluctuates, the engine controller will
constantly be making changes to the alternator field.
OPERATION
The engine controller constantly monitors battery voltage to control the alternator field voltage. The engine controller maintains a battery voltage
range of 12.9 to 15 volts. If the engine controller sees low battery voltage, it will send a higher voltage signal to the alternator field so that the
alternator will increase its charging output to the battery. When the alternator increases its charging rate it will bring the battery up to its normal
state of charge. Once the battery is fully charged, the engine controller reduces the amount of alternator field voltage.
