Hummer H2. Manual — part 29

Fig. 4: Ignition Primary Trouble Shooting Chart

STARTER TROUBLE SHOOTING

BASIC STARTER TROUBLE SHOOTING CHART

NOTE:

This is GENERAL information. This article is not intended to be specific to any
unique situation or individual vehicle configuration. The purpose of this Trouble
Shooting information is to provide a list of common causes to problem
symptoms. For model-specific Trouble Shooting, refer to SUBJECT,
DIAGNOSTIC, or TESTING articles available in the section(s) you are accessing.

CONDITION & POSSIBLE CAUSE

CORRECTION

Starter Fails to Operate

Dead battery or bad connections between
starter and battery

Check battery charge and all wires and

connections to starter

Ignition switch faulty or misadjusted

Adjust or replace ignition switch

Open circuit between starter switch
ignition terminal on starter relay

Check and repair wires and connections as

necessary

Starter relay or starter defective

See Testing in STARTER article

Open solenoid pull-in wire

See Testing in STARTER article

Starter Does Not Operate and Headlights Dim

Weak battery or dead cell

Charge or replace battery as necessary

Loose or corroded battery connections

Check that battery connections are clean

and tight

Internal ground in starter windings

See Testing in STARTER article

Grounded starter fields

See Testing in STARTERS

Armature rubbing on pole shoes

See STARTER article

Starter Turns but Engine Does Not Rotate

Starter clutch slipping

See STARTER article

Broken clutch housing

See STARTER article

Pinion shaft rusted or dry

See STARTER article

Engine basic timing incorrect

See Ignition Timing in TUNE-UP article

Broken teeth on engine flywheel

Replace flywheel and check for starter

pinion gear damage

Starter Will Not Crank Engine

Faulty overrunning clutch

See STARTER article

Broken clutch housing

See STARTER article

Broken flywheel teeth

Replace flywheel and check for starter

pinion gear damage

Armature shaft sheared or reduction gear
teeth stripped

See STARTER article

1998 Chevrolet Pickup C1500

GENERAL INFORMATION Trouble Shooting - Basic Procedures

Weak battery

Charge or replace battery as necessary

Faulty solenoid

See On-Vehicle Tests in STARTER

article

Poor grounds

Check all ground connections for tight

and clean connections

Ignition switch faulty or misadjusted

Adjust or replace ignition switch as

necessary

Starter Cranks Engine Slowly

Battery weak or defective

Charge or replace battery as necessary

Engine overheated

See ENGINE COOLING SYSTEM

article

Engine oil too heavy

Check that proper viscosity oil is used

Poor battery-to-starter connections

Check that all between battery and starter

are clean and tight

Current draw too low or too high

See Bench Tests in STARTER article

Bent armature, loose pole shoes screws or
worn bearings

See STARTER article

Burned solenoid contacts

Replace solenoid

Faulty starter

Replace starter

Starter Engages Engine Only Momentarily

Engine timing too far advanced

See Ignition Timing in TUNE-UP article

Overrunning clutch not engaging properly

Replace overrunning clutch. See

STARTER article

Broken starter clutch

See STARTER article

Broken teeth on engine flywheel

Replace flywheel and check starter pinion

gear for damage

Weak drive assembly thrust spring

See STARTER article

Weak hold-in coil

See Bench Tests in STARTER article

Starter Drive Will Not Engage

Defective point assembly

See Testing in STARTER article

Poor point assembly ground

See Testing in STARTER article

Defective pull-in coil

Replace starter solenoid

Starter Relay Does Not Close

Dead battery

Charge or replace battery as necessary

Faulty wiring

Check all wiring and connections leading

to relay

Neutral safety switch faulty

Replace neutral safety switch

Starter relay faulty

Replace starter relay

Starter Drive Will Not Disengage

Starter motor loose on mountings

Tighten starter attach bolts

1998 Chevrolet Pickup C1500

GENERAL INFORMATION Trouble Shooting - Basic Procedures

TUNE-UP TROUBLE SHOOTING - GAS ENGINE VEHICLES

Worn drive end bushing

See STARTER article

Damaged engine flywheel teeth

Replace flywheel and starter pinion gear

for damage

Drive yolk return spring broken or missing

Replace return spring

Faulty ignition switch

Replace ignition switch

Insufficient clearance between winding
leads to solenoid terminal and main
contact in solenoid

Replace starter solenoid

Starter clutch not disengaging

Replace starter clutch

Ignition starter switch contacts sticking

Replace ignition switch

Starter Relay Operates but Solenoid Does Not

Faulty solenoid switch, switch connections
or relay

Check all wiring between relay and

solenoid or replace relay or solenoid as

necessary

Broken lead or loose soldered connections

Repair wire or wire connections as

necessary

Solenoid Plunger Vibrates When Switch is Engaged

Weak battery

Charge or replace battery as necessary

Solenoid contacts corroded

Clean contacts or replace solenoid

Faulty wiring

Check all wiring leading to solenoid

Broken connections inside switch cover

Repair connections or replace solenoid

Open hold-in wire

Replace solenoid

Low Current Draw

Worn brushes or weak

Replace brushes or brush springs as

necessary

High Pitched Whine During Cranking Before Engine Fires but Engine Fires and Cranks
Normally

Distance too great between starter pinion
and flywheel

Align starter or check that correct starter

and flywheel are being used

High Pitched Whine After Engine Fires With Key released. Engine Fires and Cranks
Normally

Distance too small between starter pinion
and flywheel

Flywheel runout contributes to the

intermittent nature

NOTE:

This is GENERAL information. This article is not intended to be specific to any
unique situation or individual vehicle configuration. The purpose of this Trouble
Shooting information is to provide a list of common causes to problem
symptoms. For model-specific Trouble Shooting, refer to SUBJECT,
DIAGNOSTIC, or TESTING articles available in the section(s) you are accessing.

1998 Chevrolet Pickup C1500

GENERAL INFORMATION Trouble Shooting - Basic Procedures

BASIC SPARK PLUG TROUBLE SHOOTING CHARTS

CONDITION & POSSIBLE CAUSE

CORRECTION

Normal Spark Plug Condition

Light Tan or Gray deposits

No Action

Electrode not burned or fouled

No Action

Gap tolerance not changed

No Action

Cold Fouling or Carbon Deposits

Overrich air/fuel mixture

Adjust air/fuel mixture, see ENGINE

PERFORMANCE section

Faulty choke

Replace choke assembly, see ENGINE

PERFORMANCE section

Clogged air filter

Clean and/or replace air filter

Incorrect idle speed or dirty carburetor

Reset idle speed and/ or clean carburetor

Faulty ignition wires

Replace ignition wiring

Prolonged operation at idle

Shut engine off during long idle

Sticking valves or worn valve guide
seals

Check valve train

Wet Fouling or Oil Deposits

Worn rings and pistons

Install new rings and pistons

Excessive cylinder wear

Rebore or replace block

Excessive valve guide clearance

Worn or loose bearing

Gap Bridged

Deposits in combustion chamber
becoming fused to electrode

Clean combustion chamber of deposits

Blistered Electrode

Engine overheating

Check cooling system

Wrong type of fuel

Replace with correct fuel

Loose spark plugs

Retighten spark plugs

Over-advanced ignition timing

Reset ignition timing see ENGINE

PERFORMANCE

Pre-Ignition or Melted Electrodes

Incorrect type of fuel

Replace with correct fuel

Incorrect ignition timing

Reset ignition timing see ENGINE

PERFORMANCE

Burned valves

Replace valves

Engine Overheating

Check cooling system

Wrong type of spark plug, too hot

Replace with correct spark plug, see

ENGINE PERFORMANCE

Chipped Insulators

Severe detonation

Check for over-advanced timing or

1998 Chevrolet Pickup C1500

GENERAL INFORMATION Trouble Shooting - Basic Procedures