Starting System Principles Uses battery power

AUTOMOTIVE STARTING SYSTEMS Starter Circuit Electric DC Motor (starter motor) Solenoid or Relay Gear Drive Switches & Controls Wiring Testing Removing Starter

STARTING SYSTEM PARTS Battery Ignition switch Solenoid Starting motor

STARTER CIRCUIT Battery / Cables Magnetic Switches Solenoids Pull in Windings Hold in Windings Pinion Gear Starter Relay

Starter Circuit Simplified

Starter Solenoid Functions * Close battery to starter connection * Push pinion gear into fly wheel * Bypass the resistance wire of ignition circuit Move the starter drive into mesh w. flywheel Complete the starter circuit

Starting System Action Turn key Current flows to Solenoid 1 Energizes solenoid Connects current to starter motor Moves pinion forward Turns starter Motor turns flywheel Turns crankshaft Moves pistons up and down

Starter System Action cont.

Starter Motor Fundamentals Converts Electrical Energy From Battery Into Mechanical Energy TORQUE

DC MOTOR Basic Components Housings and End Frames Pole Shoes (magnets) Field Coils (windings) x 3 or 4 Armature (spins) Commutator Brushes x4

MOTOR OPERATION Magnetic Field Action made of invisible lines of force (flux) flow through wire flow around wire alike charges repel Dissimilar Charges attract(spinning action) Used to produce motion

DRIVE MECHANISM Positive engagement Solenoid-actuated Movable pole shoe Solenoid-actuated Gear reduction drive

Simple Electric Motors Wire loop field Set up between poles POLE SHOES

Changing Electricity Into Motion Place windings inside pole shoes Current through loop Fields act upon each other

Commutators and Brushes Used to keep motor spinning by controlling current passing through windings commutator Sliding electrical connection Between motor windings and brushes Many segments Insulated from each other Motor brushes Ride on comutator (slide on commutator) Carry current to spinning windings

Commutators and Brushes Increasing Motor Power several windings wires Commutator several segments constant smooth motion

Armatures Must produce HIGH torque turning power relatively high speed

Starter Armature parts shaft supports windings/armature inside housing Core (holds windings in place) made of iron (Fe) increases magnetic field strength Commutator for brush contact Windings wires

Field Windings stationary insulated wires wrapped in circular shape creates strong magnetic field around motor armature 5-10 x stronger than perminate magnets field in pole shoes acts against field in armature = motor spins

Pinion gear mechanism Pinion gear Clutch Housing

Starter Pinion Gears Small gear on armature shaft Engages to flywheel Meshes Fly Wheel Turns Engine

Overrunning Clutch Locks pinion gear in one direction Releases it in other direction Spiral grooves in shaft Allows starter motor to crank the engine Protects the starter from damage if the starter is cranked while the engine is running

Starter Solenoid High current relay Makes electrical connection between Battery & starter Electromagnetic switch Handle VERY HIGH currents

Starter Solenoid Operation Key turned (start position) Current flows through solenoids windings Produces magnetic field Pulls plunger and disc into coil windings Causes disc to touch both high current terminals Completes circuit battery to starter Current of 150-200A

Solenoid

Key Released Current disconnected Magnetic field collapses Plunger slides back Starter shuts off

Increasing Motor Power Several windings Wires Comutator Several segments Constant smooth motion

RELATED MOTOR TERMINOLOGY Left hand or right hand rule Torque Current Draw

STARTER DRIVE END Connects the armature shaft to the flywheel. Usually shifted out by the solenoid. Contains an over- running clutch for protection. Pinion gear meshes with the flywheel ring gear. Returned to the rest position by a spring.

SOLENOID A linear motor Contains two windings a pull-in and a hold-in winding. Pushes the starter drive(pinion) into mesh with the flywheel ring gear. Completes the circuit to the motor.

CONTROL CIRCUIT Starting Safety Switch Neutral Safety Switch On transmission On Clutch

Starting Motor Types classified by: kind of pinion gear engagement moveable pole shoe solenoid Movable pole shoe uses a yoke “Y” moves pinion gear hinged shoe on starter frame yoke links pole shoe & pinion gear

Internal Motor Circuits 3 common internal connections Series maximum torque torque decreases throughout cranking Shunt Less torque More constant torque Compound series/shunt good toque constant speed

Neutral Safety Switch prevents cranking unless in P or N Ford - brake on LOCATION Connected in series with the ignition switch and solenoid shifter or transmission

Starter Relay Uses small current to control a LARGER current Computer controls circuit (mV)

Starter Types Starter Mounted Solenoids plunger moves shift lever GM/Chrysler Permanent Magnet Starter Use high strength permanent magnets NOT CONVENTIONAL WINDINGS = MORE torque

Starter Motor Torque Must turn engine all components Can Not Stall Reduction starter extra set of gears increase rotating force higher speeds higher torque more constant cranking speeds

STARTER TESTING Preliminary Tests Safety Precautions Troubleshooting Procedures Battery Load Test Cranking Voltage Test Cranking Current Test Insulated Resistance Test Starter Relay By-pass Test Ground Circuit Resistance Test Voltage Drop to Control Unit Test Components

Problems Starter relay or solenoid clicks Whining Grinding Slow turn low battery charge Whining Plunger stuck Grinding Poor engagement Slow turn Low battery Internal short

Battery Load Test VAT 40 All Accessories on ½ CCA

Test Cranking Voltage Cranking Current Test Voltage Drop Test DVOM across battery Cranking Current Test Inductive Pick Up Current draw 150-200 AMPS Voltage Drop Test

Tests Test Relay Ground Circuit Resistance Test Starter Relay Bypass Test Ground test Bench test

Starter Motor Disassembly