3 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 performsmechanical operation. It is an electromagnetic switch.Starter motor engages pinion gear to ring gear (mounted on flywheel,Or torque converter).
4 STARTING SYSTEMStarting system uses battery power and an electric DC motor to turnengine 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 thesolenoid coil. This closes the contacts, connecting battery to thestarter motor.
5 STARTING SYSTEM Inside the starter motor. Starter solenoid Starter drive/bendixStarter armatureStarter brushesStarter bearings
6 STARTING SYSTEMCOMMUTATOR sliding electrical connection between the motorwindings and the brushes.Insulated from each other.Several loops of wire and acommutator with many segmentsare used to increase motor powerand smoothness.
7 STARTING SYSTEMBRUSHES ride on top of the commutator to carry battery currentto spinning windings.Replaced during starter rebuilding.
8 STARTING SYSTEMStarter Armature consists of the armature shaft, armature core,commutator and armature windings.Armature must produce high torque and high speeds.
9 STARTING SYSTEMField winding is a stationary insulated wire wrapped in a circularshape. It creates a strong magnetic field around the motor armature.
10 STARTING SYSTEMPinion Gear is attached to the starter drive and when starting thevehicle the pinion gear engages with flywheel orring gear. It is moved by the YOKE.
11 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.
12 STARTING SYSTEM Gear Reduction Starter Has an extra gear on the armature to further increase the rotating forceGear ratio between flywheel and armature is 45:1Hence, the armature turns 45 times to turn the flywheel (engine) once.This provides high cranking torque for starting.
13 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 constanttorque at varying speeds.Compound-wound motors have both series and shunt windings.They have good starting power with fairly consistent operating speeds.
14 STARTING SYSTEM Starting Solenoid If faulty it will simply make a Is a high current relay (controlled bylow current)Works as an electromagnet switchIf faulty it will simply make aclicking sound when one is attemptingto start the vehicle.
15 STARTING SYSTEMNeutral safety switch prevents the vehicle from starting while ingear. (can be adjusted)Clutch Safety Switch prevents the vehicle from starting, unless theclutch pedal is pressed. (adjustable)
16 STARTING SYSTEM When replacing a starter motor, make sure the spacer shims are of correct thicknessare installed.Shims sit in between the starterhousing and the engine block.If these shims are left out, the piniongear may not mesh with theflywheel gear properly, and mightcause damage to the ring-gear.Starter metallic grindingsound.
17 STARTING SYSTEM QUICK TESTING No crank with no headlightsDead Battery(corroded terminals)or an open in electrical circuit.Burned fuse.Burned or broken wire.
18 STARTING SYSTEM QUICK TESTING Head lights go out when crankingIndicates heavy current draw.Battery may be weak.Starter motor may be shorted.
19 STARTING SYSTEM QUICK TESTING Lights stay bright but, no crankHigh resistance or an open in starting circuit.Possibly Ignition switchWiring , solenoid, cable connections, relay, fuse.
20 STARTING SYSTEMCurrent Draw Test most of the starters draw over 200 Amps.Hookup the VATDisconnect Fuel/ignitionCrank engine for 5-10 seconds and note the voltage.Load the battery until same voltage is obtainedand record the Amp.The Amps will equal the current drawn bythe starting motor.4 Cylinder – 150/200 amps6 Cylinder – 175/250 amps8 Cylinder – 225/300 amps
21 STARTING SYSTEMVoltage Drop Test checks for high resistance across a cable/connectionDisable ignition/fuelHook voltmeter between +ve battery post and +ve starter terminalHook voltmeter between -ve battery post and starter ground.Crank the engine (5-10Sec.), Voltmeter should not read morethen 1volts.If greater:Loose electrical connections.Burned or pitted solenoid contacts.