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Hummer H1 (2002+). Manual - part 202

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Electrical System 12-35

05745159

Figure 12-66: Assembling Frame, Armature, and Pinion Housing

Figure 12-67: Solenoid Boot Installation

Starter Pinion Clearance

Adjustment

Connect battery and jumper to starter as shown
(Figure 12-68). Momentarily touch jumper to solenoid
frame to shift pinion into cranking position.

Figure 12-68: Battery and Jumper Connections

for Pinion Clearance Check

Check clearance between pinion and snap ring with feeler
gauge (Figure 12-69).

Disconnect battery.

Pinion clearance should be 0.005-0.030 in. (0.127-0.762
mm). If adjustment is necessary, remove end plate and add
or remove thrust washer(s) (Figure 12-69).

PINION HOUSING

ARMATURE

FRAME

MARK

GASKET

O-RING

COMMUTATOR

BRUSHES

SCRIBE

MARK

SCRIBE

SOLENOID

FRAME

BOOT (COAT

CORE SHAFT

WITH GREASE)

JUMPER WIRE

4-1-00

12-36

Electrical System

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Figure 12-69: Starter Pinion Clearance Measurement and Adjustment

Starter Test

Connect voltmeter, ammeter, switch and battery to starter
as shown (Figure 12-70).

CAUTION: Do not operate the starter motor for more than 10
seconds at a time. Allow the starter motor to cool at least 2
minutes between tests to avoid overheat damage.

WARNING: Starter must be secured to prevent move-
ment from start up torque. Test cables must be of a suf-
ficient gauge size to conduct starter current.

Close switch, adjust voltage to 9.5 volts on voltmeter
using carbon pile. Check rotating speed of armature with
tachometer. Read current draw on ammeter.

Maximum current draw should be 65 amps with a
minimum armature speed of 5000 rpm. If a low speed,
high current condition exists, check armature for shorts or
grounds. If a low speed, low current draw exists, inspect
starter motor for bad connections or poor brush contact.

Figure 12-70: Starter Test Connections

PINION HOUSING

ARMATURE SHAFT

MEASURE CLEARANCE

HERE WITH FEELER GAUGE

END

PLATE

ADD OR SUBTRACT

THRUST WASHERS TO

ADJUST CLEARANCE

SWITCH

STARTER

MOTOR

AMMETER

CARBON

PILE

VOLTMETER

12 VOLT
BATTERY

4-1-00

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Electrical System 12-37

05745159

Starter Inoperative

Step

Action

Value(s)

Yes

Inspect battery condition and charge (Refer to
battery checking procedure this section). Are bat-
teries in good working condition and charged?

Go to step 2

Recharge/Replace
batteries as neces-
sary

Using a DVOM set to measure voltage, place the
ground lead on a known good ground, and the
positive lead on the large blue wire at the starter
solenoid (CKT34).Have a helper turn the key to
start. Does the meter display adequate voltage?

12v

Repair or replace
starter and/or sole-
noid as necessary

Go to step 3

Using a DVOM set to measure resistance, mea-
sure resistance between starter body and ground
terminal at the batteries. Does resistance meet
specifications?

<.2

Ω

go to step 4

Repair open or
bad connection in
ground circuit
between starter
and batteries

Locate the start relay attached to the exterior fuse
box bracket.Using a DVOM set to measure volt-
age Back probe the 10 ga. lt.blue wire (CKT34).
Rotate the ignition to start. Is voltage present?

12v

Repair open or
short to ground in
CKT34 between
the start relay and
the starter sole-
noid.

Go to step 5

Using a DVOM set to measure voltage, place the
ground lead on a known good ground, and the
positive lead on the 10 ga. yel wire(CKT37) at the
start relay.Is voltage present ?

12v

Go to step 6

Repair open or
short to ground in
CKT37 be-tween
start relay and bat-
teries.

Using a DVOM set to measure voltage, place the
ground lead on a known good ground, and the
positive lead on the small light blue wire at the
start relay (CKT32). Rotate the ignition to start.
Does the meter display adequate voltage?

12v

Go to step 7

Go to step 8

Using a DVOM set to measure ohms, place the
negative lead on a known good ground and probe
the black wire at the start relay(CKT59). With the
ignition switch off, does resistance read below
specified?

<.2

Ω

Replace Start
Relay.

Repair open or bad
connection in
CKT59 between
start relay and
ground.

Disconnect the white wire (CKT33) at the shifter
under the vehicle. Using a DVOM set to measure
voltage, place the negative lead on a known good
ground, and the positive lead on the white wire
(CKT33) on the vehicle body harness. Have a helper
rotate the key to start. Is adequate voltage displayed?

12v

Go to step 9

Go to step 11

Disconnect the blue wire(CKT32)at the shifter
housing. Tag leads for installation. Using a
DVOM set to measure ohms, measure resistance
across the neutral safety switch. Is resistance
below specification?

<.2

Ω

Go to step 10

Replace neutral
safety switch and
recheck.

4-1-00

12-38

Electrical System

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Repair open or bad connection in CKT32
between neutral saftey switch and start relay.
Is condition repaired

Repair complete

Go to step 1.

Remove lower cover of steering column to access
the ignition switch connector. Back probe the
white wire (CKT33) with the positive lead of a
DVOM set to measure voltage. Place the ground
lead on a known good ground. Turn the ignition
switch to crank. Is voltage present?

12v

Repair open or
short to ground in
CKT33 between
Ignition switch and
the neutral saftey
switch.

Go to step 12

Using a DVOM set to measure voltage, place the
negative lead on known good ground and back-
probe the yellow wires (CKT37) at the ignition
switch connectors. Is voltage present?

12v/12v

Replace ignition
switch.

Repair open or
short to ground in
CKT37 between
maxi fuse and Igni-
tion switch.

Starter Inoperative (Continued)

Step

Action

Value(s)

Yes

4-1-00

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