STARTING SYSTEM

STARTING SYSTEM

STARTING SYSTEMBattery provides the current to turn

the starter motor.

Fuse protects the circuit.

Ignition switch closes the circuit.

Relay uses small amount of current to control large amount.

Neutral safety switch opens the circuit until the vehicle is in neutral

(manual transmission), or park (Automatic). (Can be adjusted)

Solenoid does the same thing as relay, but performs

mechanical operation. It is an electromagnetic switch.

Starter motor engages pinion gear to ring gear (mounted on flywheel,

Or torque converter).

STARTING SYSTEM•Starting system uses battery power and an electric DC motor to turn

engine crankshaft for engine starting.

•Changes electrical energy to mechanical.

•Provides gear reduction/torque multiplication (16:1 to 20:1).

•When the ignition key is turned on the current flows through the

solenoid coil. This closes the contacts, connecting battery to the

starter motor.

STARTING SYSTEM

Inside the starter motor.

1. Starter solenoid

2. Starter drive/bendix

3. Starter armature

4. Starter brushes

5. Starter bearings

STARTING SYSTEMCOMMUTATOR sliding electrical connection between the motor

windings and the brushes.

•Insulated from each other.

•Several loops of wire and a

commutator with many segments

are used to increase motor power

and smoothness.

STARTING SYSTEMBRUSHES ride on top of the commutator to carry battery current

to spinning windings.

•Replaced during starter rebuilding.

STARTING SYSTEM

Starter Armature consists of the armature shaft, armature core,

commutator and armature windings.

•Armature must produce high torque and high speeds.

STARTING SYSTEM

Field winding is a stationary insulated wire wrapped in a circular

shape. It creates a strong magnetic field around the motor armature.

STARTING SYSTEM

Pinion Gear is attached to the starter drive and when starting the

vehicle the pinion gear engages with flywheel or

ring gear. It is moved by the YOKE.

STARTING SYSTEM

Overrunning Clutch Starter

•Locks it in one direction and unlocks it in another.

•It allows the pinion gear to run free when engine begins to run.

STARTING SYSTEMGear Reduction Starter

•Has an extra gear on the armature to further increase the rotating force•Gear ratio between flywheel and armature is 45:1

•Hence, the armature turns 45 times to turn the flywheel (engine) once.

•This provides high cranking torque for starting.

STARTING SYSTEMDC electric motors have three common types of internal connections:

Series-wound motors develop maximum torque at initial start-up.

Torque decreases as motor speed increases.

Shunt-wound motors have less starting torque but more constant

torque at varying speeds.

Compound-wound motors have both series and shunt windings.

They have good starting power with fairly consistent operating speeds.

STARTING SYSTEMStarting Solenoid

•Is a high current relay (controlled by

low current)

•Works as an electromagnet switch

•If faulty it will simply make a

clicking sound when one is attempting

to start the vehicle.

STARTING SYSTEMNeutral safety switch prevents the vehicle from starting while in

gear. (can be adjusted)

Clutch Safety Switch prevents the vehicle from starting, unless the

clutch pedal is pressed. (adjustable)

STARTING SYSTEM

When replacing a starter motor, make sure

the spacer shims are of correct thickness

are installed.

•Shims sit in between the starter

housing and the engine block.

If these shims are left out, the pinion

gear may not mesh with the

flywheel gear properly, and might

cause damage to the ring-gear.

•Starter metallic grinding

sound.

STARTING SYSTEMQUICK TESTING

No crank with no headlights

•Dead Battery(corroded terminals)

or an open in electrical circuit.

•Burned fuse.

•Burned or broken wire.

STARTING SYSTEMQUICK TESTING

Head lights go out when cranking

•Battery may be weak.

•Indicates heavy current draw.

•Starter motor may be shorted.

STARTING SYSTEMQUICK TESTING

Lights stay bright but, no crank

•High resistance or an open in starting circuit.

•Possibly Ignition switch

•Wiring , solenoid, cable connections, relay, fuse.

STARTING SYSTEMCurrent Draw Test most of the starters draw over 200 Amps.

•Hookup the VAT

•Disconnect Fuel/ignition

•Crank engine for 5-10 seconds and note the voltage.

•Load the battery until same voltage is obtained

and record the Amp.

•The Amps will equal the current drawn by

the starting motor.

4 Cylinder – 150/200 amps

6 Cylinder – 175/250 amps

8 Cylinder – 225/300 amps

STARTING SYSTEM

Voltage Drop Test checks for high resistance across a cable/connection

•Disable ignition/fuel

•Hook voltmeter between +ve battery post and +ve starter terminal

•Hook voltmeter between -ve battery post and starter ground.

•Crank the engine (5-10Sec.), Voltmeter should not read more

then 1volts.

If greater:

•Loose electrical connections.

•Burned or pitted solenoid contacts.

STARTING SYSTEM