12-1

ELECTRICAL SYSTEM

1. Starter

1.1 Inspection before Disassembly(inspection of assembly)

If an abnormality is found, disassemble and repair.

(1) Pinion gap

(a) Connect the positive (+) cable of the battery toterminal S of the starter and the negative (-) cableto the starter body to extend the pinion.

(b) Lightly press the tip of the extended pinion shaftwith a finger, and measure the distance of the shaftmovement.

(c) If the measured value is not within a range of 0.5to 2.0 mm (0.0196 to 0.0787 in.), increase ordecrease the number of packings at the magneticswitch section for adjustment. An increase ofpackings results in a decrease of the pinion gap.

(2) No-load test

(a) As shown in the diagram, connect an ammeter,voltmeter, revolution indicator and battery.

(b) Turning on the switch should extend the pinion andoperate the starter at the specified speed or faster.If the current or rotating speed does not conform tothe standard value, disassemble the starter forinspection and repair.

Lightly pressthe tip

0.5 to 2.0 mm(0.0197 to 0.0787 in.)

Battery12 V

Starter

S

+ −

Inspection of pinion gap

Revolution indicator

Stater

Switch

Ammeter

V

A

Battery12 V

+−

No-load test

CAUTION

Do not supply electricity for more than 10continuous seconds.

CAUTION

(1) Use thick wires, and tighten the connectionsat the terminals.

(2) It should be noted that the rotation sound islouder than the sound produced by a starterwithout a reduction gear mechanism.

(3) When measuring the rotation speed at thetip of the pinion, be careful of the pinionextension at the start of operation.

ItemStandard

Value

Starter model M8T75171

Nominal output V-kW 12-2.2

No-load Terminal voltage V 11characteristics

Current A 130 or lower

Rotation speed 3800min−1 or higher

12-2

ELECTRICAL SYSTEM

(3) Inspection of magnetic switch

Conduct the following inspection. If the magnetic switch isfaulty, replace.

(a) Disconnect the wire from terminal M.

(b) Suction test

Connect the battery to terminals S and M of themagnetic switch. The pinion should extend when theswitch is turned on.

(c) Holding test

With the battery connected to terminals S and the bodyof the magnetic switch, pull out the pinion fully withfingers. The pinion should not return to the originalposition when it is released.

(d) Return test

With the battery connected to terminals M and the bodyof the magnetic switch, pull out the pinion fully withfingers. The pinion should return immediately to theoriginal position when it is released.

Disconnect connector

M

S

Battery12 V

_ +

Suction test

Disconnect connector

Battery12 V

M

S

+ _

Holding test

Disconnect connectorM

Battery12 V

+ _

Return test

CAUTION

Do not supply electricity for more than 10continuous seconds.

CAUTION

Do not supply electricity for more than 10continuous seconds.

CAUTION

Do not supply electricity for more than 10continuous seconds.

12-3

ELECTRICAL SYSTEM

1.2 Disassembly

13

16

1

6

5

7

15

11

14

9

4

3

2

Pole and field coilinstallation conditions.

12

Check for rotation.

Check for rotation.

Surface clearness of commutator, seizure, wear, worn or damaged gear, and disconnection.

Accumulation of brush dust, uneven wear or sticking in holder.

Check for wearor damage.

Replace snap ring.

18

8

17

Check gear for wornor damaged teeth.

Replace washer.

Check for slippageor seizure.

Disassembly sequence

1 Pinion set2 Magnetic switch3 Rear bracket4 Brush holder assembly5 Yoke assembly6 Armature

7 Bearing8 Ball9 Packing set

10 Gear11 Lever assembly12 Washer set

13 Gear shaft14 Internal gear15 Overrunning clutch16 Front bracket 17 Bearing18 Oil seal

12-4

ELECTRICAL SYSTEM

(1) Removing pinion

Supply electric current to the switch to set the pinion in theprotruded condition. Remove the M-terminal connector,and connect the battery and starter, as shown in the diagram.Close switches S1 and S2 to set the pinion in the protrudedcondition. Then, open switch S2 to stop the pinion rotation.Set a pipe-shape tool on the pinion stopper, and lightly tapthe tool with a hammer to remove the pinion.In some cases, the stopper does not dislodge from theposition and the pinion retracts into the original position.When this happens, repeat the procedure.

(2) Ball

The ball serving as the bearing in the armature thrustdirection may be stuck to grease on the tip of the shaft whenthe armature is removed. Do not loose this bearing ball.

Battery

S1

S2

S

B

M

Stater

+

−

Removing pinion

CAUTION

Before disassembling or replacing the followingparts, remove the pinion.

Remove the pinion before disassembling:

(1) Front bracket, or bracket bearing and oilseal

(2) Reduction gears

(3) Overrunning clutch

12-5

ELECTRICAL SYSTEM

1.3 Inspection

(1) Armature

(a) Testing for short circuits

Place the armature on a growler, and slowly revolve itwith a hacksaw blade held above the armature core.The hacksaw blade vibrates against the core when it isabove a slot containing a shorted winding. Replace thearmature if shorted.

(b) Testing for grounded circuits

If there is any continuity between the commutator andshaft (or core), the armature is grounded and should bereplaced.

(c) Inspecting commutator

1) Support the armature in V-blocks and measure therunout of the commutator with a dial indicator. Ifthe runout is near the service limit, recondition thecommutator, making sure the commutator diameterdoes not exceed the service limit.

Unit: mm (in.)

2) Measure the diameter of commutator. If it issmaller than the service limit, replace the armature.

Unit: mm (in.)

ItemAssembly ServiceStandard Limit

Runout of commutator 0.05 (0.002) 0.10 (0.004)

Testing short circuits

Testing grounded circuits

Measuring the runout

Measuring the diameter

ItemAssembly ServiceStandard Limit

Diameter of 32 (1.26) 31.4 (1.236)

commutator

12-6

ELECTRICAL SYSTEM

3) Measure the depth of each mold between segmentswith a depth gauge. If the depth is less than therepair limit, recondition the mold.

Unit: mm (in)

4) Inspecting armature gear

Check the armature gear for abnormal wear andmissing teeth, and replace it if necessary.

(2) Field coil

(a) Testing for open circuits

If there is no continuity between the lead wire andpositive (+) brush, the field coil is open and the yokeassembly should be replaced.

(b) Testing for grounded circuits

If there is no continuity between the yoke and positive(+) brush, the insulation and repair or replace the yokeassembly.

ItemAssembly RepairStandard Limit

Depth of 0.4 to 0.6 0.2 (0.008)commutator mold (0.016 to 0.024) or less

Mold depth

Segment

Measuring the mold depth

Testing yoke coil for open circuit failure

Testing yoke coil for grounding failure

12-7

ELECTRICAL SYSTEM

(3) Magnetic switch

(a) Testing coil for open circuits

If there is no continuity between S and M terminalsand between S terminal and body (ground) , replace theswitch.

(b) Checking contactors for fusion

If there is continuity between B and M terminals,replace the switch.

(c) Checking contactors for poor contact action

Check for voltage drop. If voltage drop is excessive,the contactors are defective.

(4) Brushes and holders

(a) Wear of brushes

Measure the brush length and, if it is less than theservice limit, replace the brushes. If the brushes areunevenly worn or rough, recondition them with asandpaper of #300 to #500.

Unit: mm (in)

(b) Brush spring force

Test the spring force using a new brush. In the test,read the road at the instant the spring moves off thebrush. If the force is less than the service limit, replacethe spring.

Unit: N (kgf) [lbf]

ItemAssembly ServiceStandard Limit

Length of brush 18 (0.71) 11 (0.43)

ItemAssembly ServiceStandard Limit

26 to 36 15Force of brush spring (2.7 to 3.7) (1.5)

[5.8 to 8.1] [3.4]

Brush

Measuring brush length

B terminal

S terminal

M terminal

Testing magnetic switch

Measuring rush spring force

12-8

ELECTRICAL SYSTEM

(c) Testing brush holders insulation

If there is any continuity between the positive (+) brushholder and negative (-) holder plate, replace the brushholder assembly.

(5) Inspecting bearings

Check the bearings and replace any that fails to turnsmoothly or emits noise.

(6) Inspecting overrunning clutch

(a) Make sure that the pinion shaft turns freely whenturned in the direction of driving (clockwise) and itis locked when turned in the opposite direction.

(b) Check the overrunning clutch for worn-out ordamaged pinion, and replace it if necessary.

(7) Front bracket

If the ball bearing fails to turn smoothly or emits noise,replace it together with the front bracket.

(8) Reduction gear

Replace the reduction gear if it is worn out or damaged.

Testing brush holders insulation

Inspecting overrunning clutch

CAUTION

Do not wash overrunning clutch in wash oil.

NOTE

Replace the oil seal at every disassembly.

12-9

ELECTRICAL SYSTEM

(2) Installing stopper ring

Fit the stopper ring into the ring groove on the pinion shaft.Then, using a puller, pull the pinion stopper over thestopper ring to fit the stopper ring into the ring grooveinside the pinion stooper.

1.4 Reassembly

To reassemble, follow the disassembly sequence in reverse.

(1) Applying grease

When overhauling the starter, apply grease to the following sliding parts, gears, and bearings.

Reassembly sequence

1 Armature shaft gear2 Armature rear bearing (Slightly. Be careful not

to let the grease enter the commutator.)

3 Reduction gear 4 Pinion shaft gear

5 Lever sliding section of magnetic switch6 Pinion shaft bearing7 Pinion8 Oil seal

2

3 1 5 46

8

7

Pinion stopper

Pinion stopper

Stopper ring

Installing stopper ring

12-10

ELECTRICAL SYSTEM

(3) Adjusting pinion shaft end play

Using an appropriate number of adjusting washers inbetween the center bracket and reduction gear, adjust theend plate (thrust gap) to 0.5 mm (0.020 in.) or less.

(a) Assemble the pinion shaft, reduction gear, washerand snap ring to the center bracket.

(b) Moving the pinion shaft in the axial direction,measure its end play. If the end play exceeds 0.5mm (0.020 in.), increase the number of adjustingwasher as required to reduce it to 0.5 mm (0.020in.) or less.

(4) Installing lever

Install the lever facing in the correct direction.

1.5 Inspection and Adjustment afterAssembly

Following inspections and tests shall be performed afterstarter assembling.

(1) Checking pinion gap

With the pinion fully protruded, lightly press the pinionshaft end back with a finger. Measure the extent of shaftreturn to determine if the pinion gap is larger or smaller than0.5 to 2.0 mm (0.0196 to 0.0787 in.). Make adjustment, ifnecessary, with the packing provided where the magneticswitch is fitted; increase the number of pieces of packing ifthe gap is larger and decrease otherwise.

(2) No-load test

After adjusting the pinion clearance, hook up the starter asshown, and test it for no-load characteristics.

CAUTION

Use thick wires as much as possible and tighteneach terminal securely.

Item Voltage Current Speed

No-load11 V

130 A 3800 min−1

characteristic or less or less

End play0.5 mm (0.020 in.)max.

Snap ring

Washer

Reduction gearAdjusting washer

Adjusting pinion shaft end play

Front bracket

LeverLever spring

Packing

Installing lever

Lightly pressthe tip

0.5 to 2.0 mm(0.0196 to 0.0984 in.)

Battery12 V

Starter

S

+ −

Adjusting pinion gap

A

V

B

MS

Ammeter

Switch

SwitchBattery

Voltmeter

No-load test

12-11

ELECTRICAL SYSTEM

Alternator

2. Alternator

If a problem occurs in the charge system, check thefollowing abnormal conditions to locate the cause of theproblem. Only when inspection cannot be conducted onthe alternator installed on the engine, dismount thealternator for inspection and repair.

2.1 On-vehicle Inspection

(1) Cautions in handling

Handle the alternator carefully. Incorrect handling canresult in alternator damage and malfunctions.

(a) Do not connect the battery cables in reverse. Notethat the negative cable is a grounding wire.

(b) Do not use a high-voltage tester such as a megger.

(c) When charging the battery, disconnect the cablesfrom the battery terminals.

(d) Do not disconnect the lead wire from terminal B ofthe alternator while the engine is operating.

(e) Do not ground terminal B of the alternator since itis constantly applied with battery voltage.

(f) Do not short or ground terminal L (unit withintegrated IC regulator).

(g) When using a steam cleaner, do not allow steam todirectly contact the alternator.

Over- Voltage regulator adjustment value is high.charging

Faulty battery.

Over- Voltage relay adjustment value is low.discharging

Faulty alternator output.

Power consumption is extremely high.

Special load is used.

Faulty wiring.

12-12

ELECTRICAL SYSTEM

(2) Inspection of adjustment voltage (unit with integrated IC regulator)

(a) Disconnect the cable from the positive (+) terminalof the battery, and connect an ammeter between theterminal and cable.

(b) Connect a voltmeter between terminal L andground.

(c) Make sure that the voltmeter indicates “0” whenthe starter switch is turned off.Make sure that the voltmeter indicates a voltagelevel sufficiently lower than the battery voltagewhen the starter switch is turned on (withoutstarting the engine).

(d) Short-circuit the terminal of the ammeter, and startthe engine.

(e) Read the indication (adjustment voltage) on thevoltmeter with the ammeter indicating 5 A orlower, the engine operating at 1800 to 2500 min-1,and the lamp switches turned off.

(3) Inspection of output (unit with integrated IC regulator)

(a) Disconnect the grounding cable from the battery.

(b) Disconnect the wire from terminal B of thealternator, and connect an ammeter. Connect avoltmeter between terminal B and ground.

(c) Connect the grounding cable to the battery.

(d) Start the engine.

(e) Immediately after the engine starts, turn on all loaddevices such as lamps.

(f) Increase the engine speed. When the voltmeterindicates 13.5 V, read the maximum current at thespecified alternator rotation speed.If the measured value conforms to the standardvalue, the alternator is normal.

Ammeter

SwitchL

R

Voltmeter

Battery

12 V

A

V+

+ −

+ −

Inspection of adjustment voltage

Ammeter

Voltmeter Chargelamp

Switch

A

VB

L

R

+

Wiring diagram for output test (unit with integrated IC regulator)

Unit: V

Item Standard Value V-A

Adjustment voltage 14.7±0.3 12-50

at 20°C (68°F)

Output characteristics

Standard Value

Item Model Terminal Rotation

voltage/current

speed

Option 13.5V/33A 2500 min-1

characteristic A7TA0477A(when warm) 13.5V/47A 5000 min-1

12-13

ELECTRICAL SYSTEM

2.2 Disassembly

Check for rotation.

Check for rotation.

3

4

1

2

5Check slip rings for clearness, damage and seizure. Check for coil resistance.

10

9

7

Check for short or open circuit.

6 Check coil for disconnection or grounding.

8

Check for sliding conditionand wear of brush.

Disassembly sequence

1 Nut2 Pulley, Spacer3 Screw4 Front bracket assembly

5 Rotor assembly6 Stator7 Rear bracket8 Regulator assembly

9 Rectifier assembly10 Nut set

12-14

ELECTRICAL SYSTEM

Key points in disassembly

(1) Separation of front bracket from stator core

(a) Insert the tip of a slotted screwdriver into the gapbetween the stator core and front bracket, and pryopen.

(2) Removal of pulley

(a) Wrap the rotor with a cloth for protection, and holdit with a vice. Unscrew the pulley nut, thenremove the pulley and spacer.

(b) Remove the rotor from the front bracket.

(3) Removal of stator core and rectifier

(a) Disconnect the lead wires from the stator core tothe rectifier at the soldered sections. Then, removethe stator core.

(b) Unscrew the rectifier mounting screws, anddismount the rectifier.

CAUTION

Do not insert the screwdriver too deep into theassembly to prevent damage to the stator core.

CAUTION

Melt the soldered sections as quickly aspossible. If heat is applied for an extendedperiod of time, the diodes can be damaged.

Disassembly of alternator

Removal of pulley

Rectifier

Solenoid section

Solenoid sections

Removal of stator core

12-15

ELECTRICAL SYSTEM

2.3 Inspection

Key points in inspection

(1) Inspecting diodes

For inspection of individual diodes, check the resistancebetween each diode lead and heat sink. Take resistancemeasurements by connecting the positive (+) wire of atester to the diode and also by connecting the negative (-)wire to the diode. If the resistance shows “infinite” in bothmeasurements, there is an open circuit. If the resistance isclose to 0 in both measurements, there is a short circuit.If there is an open or short circuit, the diode is faulty andthe rectifier must be replaced.

(2) Inspecting field coil

(a) Check the resistance between slip rings and if themeasurement does satisfy the standard value,replace with a new rotor.

(b) Check the continuity between the slip ring andshaft (or core). If there is electric conduction, the field coil isgrounded: replace the rotor with new one.

Trio diodes

(−) heat sink

(+) heat sink Diode lead

Inspecting diodes

Field coil continuity

Field coil grounding test

Item Standard Value

Resistance between slip rings 2.7 to 3.2 ohm

12-16

ELECTRICAL SYSTEM

Stator core continuity test

Stator core grounding test

(3) Inspecting stator core

(a) Check the continuity between the stator core andeach lead wire.If there is no electric conduction, there is an opencircuit: replace the stator core with new one.

(b) Check to make sure that there is no continuitybetween the lead wires and core.If there is continuity, the circuit is grounded:replace the stator with new one.

(4) Inspecting brushes

(a) If the brushes are worn close to the wear limit line(service limit), replace the brushes.

Unit: mm (in.)

(b) Disconnect the brush lead wires at the solderedsections to remove the brushes and springs.

Item Assembly Standard Service Limit

Brush length 18.5 (0.728) 5 (0.197)

5 mm (0.197 in.)

Wear limit line18.5 mm(0.728 in.)

Inspecting brush

Soldered sections

Replacement of brushes

12-17

ELECTRICAL SYSTEM

(c) To install new brushes, press them into the brushholders as shown in the illustration, then solder the leadwires.

2.4 Reassembly

To reassemble, follow the disassembly sequence in reverse.

Be sure to observe the following during assembly.

Key points in reassembly

(1) When press-fitting the rear bearing into the rearbracket, heat the rear bracket to 50 to 60°C (122 to140°F).

(2) The brushes must be raised before the rotor is installedto the rear bracket. To do so, put a wire through thesmall hole located on the rear bracket, then remove thewire after completing the reassembly.

2.5 Installation

(1) Install the fan belt on the alternator, and mount thealternator on the engine.Temporarily tighten all the bolts.

(2) Insert a bar between the alternator and crankcase.Using the bar as leverage, move the alternator andadjust the belt tension.While keeping the alternator at that position, tightenthe bolt that secures the alternator to the adjustingplate.

Replacement of brushes

Wire

Rear bracket

Brush

Wire

Reassembly of alternator

Installation of alternator

12-18

ELECTRICAL SYSTEM

(3) Check the belt tension. If the belt tension does notconform to the standard value, loosen the belt andrepeat the above step (2).

Unit: mm (in.)

(4) When the belt tension is properly adjusted, tighten allthe bolts that secure the alternator in place.

3. Glow Plugs

3.1 Inspection

As shown in the illustration, check the conductivitybetween the terminal and body. If there is no conductivityor if the resistance is high, replace the glow plug.

3.2 Installation

(1) Install the glow plug in the cylinder head by tighteningto the specified torque.

(2) Install the connection plate to the glow plug, andtighten the retaining nut to the specified torque.

Inspecting glow plug

Item Standard Value

Belt tension 10 to 12 (0.39 to 0.47)(crankshaft pulley – (when pressed with force of alternator pulley) 98 N (10 kgf) [22 lbf])

Water pumppulley

CrankshaftpulleyBolt

Bolt

Alternator pulley

Adjusting plate

98 N(10 kgf)[22 lbf]

10 to 12 mm(0.39 to 0.47 in.)

Inspection of belt tension

Item Assembly Standard

Resistance 0.2 ohm

18±2 N·mTightening torque (1.8±0.2 kgf·m)

[13±1 lbf·ft]

1.3±0.2 N·mTightening torque (0.13±0.02 kgf·m)

[0.96±0.14 lbf·ft]

12-19

ELECTRICAL SYSTEM

4. Magnet Valve (Stop Solenoid)

4.1 Inspection

(1) Check the conductivity between the terminal and bodyas shown in the illustration. If there is no conductivityor if the resistance is lower than the standard value,replace the magnet valve assembly.

(2) Check visually for rubber strips of the tip of thearmature and damages. Also check the armature movessmoothly by rotating with a hand.

4.2 Installation

Install the magnet assembly to the distributor with thespecified torque.

Checking magnet valve (1)

Armature

Checking magnet valve (2)

Magnet valveassembly

Injection pumpdistributor head

Installing magnet valve

Item Standard Value

Resistance8 to 9.2 ohm

[Ambient Temp: 23±5°C (73.4±9°F)]

20±5 N·mTightening torque (2±0.5 kgf·m)

[15±3.6 lbf·ft]