1. Starting System
Fundamentals

2. Starting System Principles
The starting system uses battery power and an electric motor to turn the engine crankshaft for engine starting
History Video

3. Basic Starting System
The ignition key switch energizes the solenoid, which allows the battery to energize the starting motor, which then turns the flywheel gear, rotating the engine until it starts.

4. Components Battery Ignition key switch Solenoid Starting motor
source of energy
Ignition key switch
allows the driver to control operation
Solenoid
high current relay (switch)
Starting motor
high-torque electric motor

5. Starting Motor Fundamentals
Converts electrical energy from the battery to mechanical energy to crank the engine
How Starter Motor Works Video

6. Starter-Mounted Solenoid
Solenoid plunger moves a lever to engage the pinion gear

7. Starter-Mounted Solenoid
The solenoid not only operates the pinion gear but also completes the battery-to-starter circuit

8. Solenoid Operation

9. Simple Electric Motor
If a current-carrying winding is placed inside a magnetic field, the winding rotates away from the poles. Explanation Video

10. Starter Pinion Gear
Small gear on the armature shaft engages a large ring gear on the engine flywheel.
Animation

11. Neutral Safety Switch
Prevents the engine from cranking unless the shift selector is in neutral or park
Mounted on the shift lever or on the transmission

12. Energizing the Starting System
Turning the ignition key to the “start” position allows current to flow through the solenoid coil
Magnetism closes the solenoid contacts, connecting the battery to the starting motor
The motor turns the flywheel ring gear until the engine runs on its own

13. De-energizing the Starting System
When the ignition key is released to the “run” position, no current flows to the solenoid coil
The solenoid contacts open, the starter stops turning, and the starter gear moves away from the flywheel

14. The End