Download starting system

STARTING SYSTEM
STARTING SYSTEM
STARTING SYSTEM
Battery 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.
2.
3.
4.
5.
Starter solenoid
Starter drive/bendix
Starter armature
Starter brushes
Starter bearings
STARTING SYSTEM
COMMUTATOR 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 SYSTEM
BRUSHES 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 SYSTEM
Gear 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 SYSTEM
DC 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 SYSTEM
Starting 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 SYSTEM
Neutral 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 SYSTEM
QUICK TESTING
No crank with no headlights
•Dead Battery(corroded terminals)
or an open in electrical circuit.
•Burned fuse.
•Burned or broken wire.
STARTING SYSTEM
QUICK TESTING
Head lights go out when cranking
•Indicates heavy current draw.
•Battery may be weak.
•Starter motor may be shorted.
STARTING SYSTEM
QUICK 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 SYSTEM
Current 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