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