Charging System: Description and Operation

Charging System

The charging system is a negative ground system consisting of the following components:

- Generator(s)

- Internal voltage regulator

- Charging system warning indicator

- Battery

- Circuitry and cables

Generator

The charging system is a negative ground system. The generator is belt-driven by the engine accessory drive system. When the engine is started, the generator begins to generate AC current, which is internally converted to DC. This current is then supplied to the vehicle electrical system through the output (B+) terminal of the generator.

The generator system consists of the generator mounted on the top center of the engine. A 120-amp generator with a 2.72:1 pulley ratio is standard. An extra heavy-duty option is available which includes a 155-amp generator with a 2.72:1 pulley ratio. A super heavy-duty option is also available which includes a 225-amp generator with a 3.00:1 pulley ratio.

The generators are similar in appearance and use the same connectors, making them interchangeable, although wiring lengths vary so a wiring change may be desired. Identification between the different generators can be carried out by referring to the generator engineering number and the parts catalog.

The set voltage varies with temperature and is typically higher in cold temperatures than in warm temperatures. This allows for better battery recharge in the winter and reduces the chance of overcharging in the summer.

Battery

The battery is a 12-volt direct current source connected in a negative ground system. The battery case is sealed and includes 2 vent holes to release gases. The battery has 3 major functions:

- Engine cranking power source

- Voltage stabilizer for the electrical system

- Temporary power when electrical loads exceed the generator output current