A Circuit
WARNING: This page is about a different car, the 2005 Ford RV Cutaway, 2005 Ford Econoline, 2005 Ford E450 Super Duty, and 2005 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.
The A circuit or battery sense circuit is used to sense battery voltage. This voltage is used by the regulator to determine the generator output.