How does the lighting circuit work on the ALT.

ANONYMOUS

MEMBER
1967 CHEVROLET EL CAMINO
179,000 MILES

How does the lighting circuit work on the Alt, Bat, etc. Typically, potential volts (12vdc) into a load (light bulb) to common or ground will control the light. Does the Alt curcuit have a high impedence resistor or something to allow dash light to be on when ignition is "on", then light turns off when engine is running and then turns from dim to bright as Alt ot Batt loses voltage? Can you clarify please and thank you.

1 Reply

ASEMASTER6371

MECHANIC
52,797 POSTS

There is power to the alt light and the ground is controlled in the alt. When the ground is interrupted, the light goes out and the alt is charging. When there is a continued ground, the alt is not charging

Roy