The basic heavy-duty electrical system consists of:

• Batteries and cables (1)
• A starting motor (2)
• An alternator (3)
• A magnetic switch (4)
• Keyswitch (5)
• A push button starter switch (6)
• Starting circuit wiring (7)

Refer to the vehicle manufacturer's service repair manual for specific service information about the charging and starting circuits.

Refer to the vehicle manufacturer's service repair manual or the component manufacturer's service bulletins for specific service information about the starting motor and the alternator.