Description & Operation

WARNING: This page is about a different car, the 2004 Lexus LS 430 and 2003 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.

The generator is a small, high RPM, high performance type with an internal Integrated Circuit (IC) voltage regulator which controls charging system voltage. A transistor inside IC regulator controls generator voltage output to maintain a constant voltage. Charging system voltage is maintained within an operating range of 13.2-14.8 volts.

When ignition is turned on, battery voltage flows from generator terminal "L" through IC regulator to ground, causing discharge warning light to come on. When engine starts, generator RPM increases, which increases generator output voltage. When generator output voltage is greater than battery voltage, voltage to recharge battery flows from terminal "B". At the same time, voltage at terminal "L" increases and the potential difference between battery and terminal "L" ceases, causing discharge warning light to go off.