Operation CHARM: Car repair manuals for everyone.

Charging System Indicator

The charging system indicator illuminates when the following occurs:
^ Generator output is less than 11 volts
^ Generator output is greater than 16 volts
^ The ignition is on, with the engine off

When the ignition switch is turned to the ON position and the generator is not rotating, the regulator provides a ground which causes a bulb check and the charge indicator illuminates. When the generator is rotating, the regulator provides a separate output voltage to the charge indicator. Since equal voltage is now provided to both sides of the charge indicator, the lamp loses its ground and goes out.