Suzuki Grand Vitara JB419. Service manual — part 68

Starting System: 1I-1

Engine

Starting System

General Description

Cranking Circuit Introduction

S5JB0B1901001

The cranking circuit consists of the battery, starting motor, ignition switch, and related electrical wiring. These
components are connected electrically.

Starting Motor Circuit Description

S5JB0B1901002

• The magnetic switch coils are magnetized when the ignition switch is closed.
• The resulting plunger and pinion drive lever movement causes the pinion to engage the engine flywheel gear and

the magnetic switch main contacts to close, and cranking takes place.

• When the engine starts, the pinion over-running clutch protects the armature from excessive speed until the switch

is opened, at which time the return spring causes the pinion to disengage.

I5JB0B190001-01

1. Pinion drive lever

5. Magnetic switch contacts

9. Starting motor

2. Plunger

6. Pinion and over-running clutch

10. Battery

3. Hold-in coil

7. Pull-in coil

11. Ignition and starting motor switch

4. Magnetic switch

8. Return spring

1I-2 Starting System:

Diagnostic Information and Procedures

Cranking System Symptom Diagnosis

S5JB0B1904001

Possible symptoms due to starting system trouble would be as follows:
• Starting motor does not run (or runs slowly)
• Starting motor runs but fails to crank engine
• Abnormal noise is heard
Proper diagnosis must be made to determine exactly where the cause of each trouble lies. .in battery, wiring harness,
(including starting motor switch), starting motor or engine.
Do not remove motor just because starting motor does not run. Check the following items and narrow down scope of
possible causes.

1) Condition of trouble
2) Tightness of battery terminals (including ground cable connection on engine side) and starting motor terminals
3) Discharge of battery
4) Mounting of starting motor

Condition

Possible cause

Correction / Reference Item

Motor not running – No
operating sound of
magnetic switch

Shift lever switch is not in P or N, or not
adjusted (A/T)

Shift in P or N, or adjust switch.

Battery run down

Recharge battery.

Battery voltage too low due to battery
deterioration

Replace battery.

Poor contact in battery terminal
connection

Retighten or replace.

Loose grounding cable connection

Retighten.

Fuse set loose or blown off

Tighten or replace.

Poor contacting action of ignition switch
and magnetic switch

Replace.

Lead wire coupler loose in place

Retighten.

Open-circuit between ignition switch and
magnetic switch

Repair.

Open-circuit in pull-in coil

Replace magnetic switch.

Brushes are seating poorly or worn
down

Repair or replace.

Poor sliding or plunger and/or pinion

Repair.

Motor not running –
Operating sound of
magnetic switch heard

Battery run down

Recharge battery.

Battery voltage too low due to battery
deterioration

Replace battery.

Loose battery cable connections

Retighten.

Burnt main contact point, or poor
contacting action of magnetic switch

Replace magnetic switch.

Brushes are seating poorly or worn
down

Repair or replace.

Weakened brush spring

Replace starting motor.

Burnt commutator

Replace starting motor.

Layer short-circuit of armature

Replace starting motor.

Crankshaft rotation obstructed

Repair.

Starting motor running,
but too slow (small
torque) – Battery and
wiring are satisfactory

Insufficient contact of magnetic switch
main contacts

Replace magnetic switch.

Layer short-circuit of armature

Replace starting motor.

Disconnected, burnt or worn
commutator

Replace starting motor.

Worn brushes

Replace starting motor.

Weakened brush springs

Replace starting motor.

Burnt or abnormally worn end bush

Replace starting motor.

Starting System: 1I-3

Starting Motor Performance Test

S5JB0B1904002

CAUTION

!

Each test must be performed within 3 – 5
seconds to avoid coil from burning.

Pull-In Test

1) Connect battery to magnetic switch as shown.
2) Check that plunger and pinion move outward. If

plunger and pinion don’t move, replace magnetic
switch.

NOTE
Before testing, disconnect lead wire from
terminal “M”.

Hold-In Test

1) While connected as above with plunger out,

disconnect negative lead (2) from terminal “M” (1).

2) Check that plunger and pinion remain out. If plunger

and pinion return inward, replace magnetic switch.

Plunger and Pinion Return Test

1) Disconnect negative lead (1) from switch body (2).
2) Check that plunger and pinion return inward. If

plunger and pinion don’t return, disassemble and
inspect starting motor.

Starting motor running,
but not cranking engine

Worn pinion tip

Replace over-running clutch.

Poor sliding of over-running clutch

Repair.

Over-running clutch slipping

Replace over-running clutch.

Worn teeth of ring gear

Replace flywheel (M/T) or drive plate (A/T).

Noise

Abnormally worn bearing

Replace front housing.

Worn pinion or worn teeth of ring gear

Replace over-running clutch, flywheel (M/T) or
drive plate (A/T).

Poor sliding of pinion (failure in return
movement)

Repair or replace.

Worn internal or planetary gear teeth

Replace.

Lack of oil in each part

Lubricate.

Starting motor does not
stop running

Fused contact points of magnetic switch Replace magnetic switch.
Short-circuit between turns of magnetic
switch coil (layer short-circuit)

Replace magnetic switch.

Failure of returning action in ignition
switch

Replace.

Condition

Possible cause

Correction / Reference Item

1. Terminal “S”
2. Terminal “M”
3. Lead wire (switch to motor)

1

2

3

I5JB0B190002-01

1

2

I5JB0B190003-01

2

1

I5JB0B190004-01

1I-4 Starting System:

No-Load Performance Test

1) Connect battery and ammeter to starter as shown.
2) Check that starter rotates smoothly and steadily with

pinion moving out. Check that ammeter indicates
specified current.

Specified current (no-load performance test)
90A MAX. at 11V

NOTE
Use wires as thick as possible and tighten
each terminal fully.

Repair Instructions

Starting Motor Components

S5JB0B1906005

A

I5JB0B190005-01

(a)

2

6

5

7

8

9

12

11

13

14

1

15

I5JB0B190006-02

1. Front housing

5. Planetary carrier shaft assembly

9. Pin

13. Over-running clutch

2. Yoke

6. Plunger / lever assembly

10. Magnetic switch inner bolt

14. Pinion stop ring