heater HUMMER H3 2008 User Guide

When the engine is cold, the coolant level should be at
least up to the FULL COLD mark. If it is not, you
may have a leak at the pressure cap or in the radiator
hoses, heater hoses, radiator, water pump or
somewhere else in the cooling system.
{CAUTION:
Heater and radiator hoses, and other engine
parts, can be very hot. Do not touch them. If
you do, you can be burned.
Do not run the engine if there is a leak. If you
run the engine, it could lose all coolant. That
could cause an engine re, and you could be
burned. Get any leak xed before you drive the
vehicle.
If there seems to be no leak, start the engine again.
The engine cooling fan speed should increase when idle
speed is doubled by pushing the accelerator pedal
down. If it does not, your vehicle needs service. Turn off
the engine.
Notice:Engine damage from running the engine
without coolant is not covered by the warranty.
Notice:Using coolant other than DEX-COOL
®may
cause premature engine, heater core, or radiator
corrosion. In addition, the engine coolant could
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs rst. Any repairs
would not be covered by the warranty. Always
use DEX-COOL
®(silicate-free) coolant in the vehicle.
5-32

How to Add Coolant to the Coolant
Recovery Tank
If you have not found a problem yet, but the coolant
level is not at the FULL COLD mark, add a 50/50
mixture of clean, drinkable water and DEX-COOL
®
engine coolant at the coolant recovery tank. SeeEngine
Coolant on page 5-27for more information.
{CAUTION:
Adding only plain water to the cooling system
can be dangerous. Plain water, or some other
liquid such as alcohol, can boil before the
proper coolant mixture will. The vehicle’s
coolant warning system is set for the proper
coolant mixture. With plain water or the wrong
mixture, the engine could get too hot but you
would not get the overheat warning. The
engine could catch re and you or others
could be burned. Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
®coolant.Notice:In cold weather, water can freeze and crack
the engine, radiator, heater core and other parts.
Use the recommended coolant and the proper
coolant mixture.
{CAUTION:
You can be burned if you spill coolant on hot
engine parts. Coolant contains ethylene glycol
and it will burn if the engine parts are hot
enough. Do not spill coolant on a hot engine.
When the coolant in the coolant recovery tank is at the
FULL COLD mark, start your vehicle.
5-33

Fuse Usage
52 StabiliTrak®, Antilock Brakes
53 Power Heater Switch
54 Stop
55 Trailer Parking Lamps
56 Front Turn Signal, Hazard Signal
57 Power Sunroof
58Transfer Case Control Module
Switch
59 Climate Control
60 Spare 8
61 Power Seats
62 Air Pump
63 Passenger Side Power Window
64Antilock Brakes, StabiliTrak
®2
Solenoid
67Antilock Brakes, StabiliTrak
®1
Motor
68 Driver Side Power Window
82 Climate Control Fan
83 Electronic Brake Controller
84 Trailer B+ Fuse
85 Starter
91 Megafuse
Relay Usage
66 Fuel Pump
69 Fog Lamp
70 High, Low Beam Headlamps
71 Rear Defogger
72 Windshield Wiper On/Off
73 Windshield Wiper High/Low
74 Horn
75 Headlamp
76 Air Conditioning Clutch
77 Powertrain Control Module
78 Run, Crank
79Reduced Intensity Low-Beam
Daytime Running Lamps
80 Air Injection Reactor (AIR) Solenoid
81 Powertrain (Starter)
86 Spare 2
87 Heating, Ventilation, Air Conditioning
88 Retained Accessory Power
89 Park Lamp
Diode Usage
65 Wiper Diode
90 Air Conditioning Clutch Diode
5-106

Child Restraints
Child Restraint Systems...............................1-37
Infants and Young Children...........................1-33
Lower Anchors and Tethers for Children..........1-42
Older Children.............................................1-30
Securing a Child Restraint in a
Rear Outside Seat Position........................1-48
Securing a Child Restraint in the
Center Rear Seat Position.........................1-50
Securing a Child Restraint in the
Right Front Seat Position..........................1-51
Where to Put the Restraint...........................1-40
Cigarette Lighter.............................................3-22
Cleaning
Aluminum or Chrome-Plated Wheels..............5-97
Exterior Lamps/Lenses.................................5-95
Fabric/Carpet..............................................5-93
Finish Care.................................................5-96
Instrument Panel, Vinyl, and Other
Plastic Surfaces.......................................5-94
Interior.......................................................5-91
Leather......................................................5-93
Tires..........................................................5-98
Underbody Maintenance...............................5-98
Washing Your Vehicle...................................5-95
Weatherstrips..............................................5-94
Windshield, Backglass, and Wiper Blades.......5-97
Climate Control System...................................3-22
Outlet Adjustment........................................3-24Clock............................................................3-48
Clutch, Hydraulic.............................................5-26
Collision Damage Repair..................................7-11
Compass...............................................2-38, 2-41
Content Theft-Deterrent....................................2-14
Control of a Vehicle.......................................... 4-3
Convenience Net............................................2-59
Coolant
Engine Temperature Gage............................3-35
Heater, Engine............................................
2-22
Cooling System..............................................5-31
Cruise Control................................................3-11
Cruise Control Light........................................3-39
Cupholder(s)..................................................2-56
Customer Assistance Information
Courtesy Transportation.................................. 7-9
Customer Assistance for
Text Telephone (TTY) Users........................ 7-5
Customer Assistance Offices........................... 7-5
Customer Satisfaction Procedure..................... 7-2
GM Mobility Reimbursement Program............... 7-6
Reporting Safety Defects to General Motors.....7-15
Reporting Safety Defects to the
Canadian Government..............................7-15
Reporting Safety Defects to the
United States Government.........................7-14
Roadside Assistance Program......................... 7-6
Service Publications Ordering Information........7-15
3

D
Daytime Running Lamps..................................3-17
Defensive Driving............................................. 4-2
Doing Your Own Service Work........................... 5-4
Dome Lamp...................................................3-19
Dome Lamp Override......................................3-20
Door
Locks.......................................................... 2-7
Power Door Locks......................................... 2-8
Programmable Automatic Door Locks............... 2-8
Rear Door Security Locks............................... 2-9
Driver Information Center (DIC).........................3-40
DIC Operation and Displays..........................3-40
DIC Warnings and Messages........................3-43
Driving
At Night.....................................................4-32
Before a Long Trip......................................4-34
Defensive..................................................... 4-2
Drunken....................................................... 4-2
Highway Hypnosis.......................................4-34
Hill and Mountain Roads..............................4-34
In Rain and on Wet Roads...........................4-33
Off-Road....................................................4-12
Recovery Loops..........................................4-40
Rocking Your Vehicle to Get it Out.................4-40
Winter........................................................4-35
E
EDR .............................................................7-16
Electrical System
Add-On Equipment.....................................5-101
Engine Compartment Fuse Block.................5-103
Fuses and Circuit Breakers.........................5-102
Power Windows and Other Power Options....5-102
Windshield Wiper Fuses.............................5-101
Engine
Air Cleaner/Filter.........................................5-20
Check and Service Engine Soon Light............3-36
Coolant......................................................5-27
Coolant Heater............................................2-22
Coolant Temperature Gage...........................3-35
Drive Belt Routing.......................................6-15
Engine Compartment Overview......................5-12
Exhaust.....................................................2-36
Fan Noise..................................................5-36
Oil .............................................................5-15
Oil Life System...........................................5-18
Overheating................................................5-29
Running While Parked..................................2-37
Starting......................................................2-20
Event Data Recorders.....................................7-17
Exit Lighting...................................................3-20
Extender, Safety Belt.......................................1-30
Exterior Lamps...............................................3-15
4

H
Hazard Warning Flashers................................... 3-6
Head Restraints............................................... 1-7
Headlamp
Aiming.......................................................5-46
Headlamps....................................................5-49
Bulb Replacement.......................................5-49
Daytime Running Lamps...............................3-17
Exterior Lamps............................................3-15
Flash-to-Pass............................................... 3-9
Halogen Bulbs............................................5-49
High/Low Beam Changer................................ 3-9
On Reminder..............................................3-16
Heated Seats................................................... 1-4
Heater...........................................................3-22
Highbeam On Light.........................................3-39
Highway Hypnosis...........................................4-34
Hill and Mountain Roads..................................4-34
Hood
Checking Things Under................................5-11
Release.....................................................5-11
Horn............................................................... 3-6
How to Wear Safety Belts Properly...................1-16
Hydraulic Clutch.............................................5-26
I
Ignition Positions.............................................2-18
Infants and Young Children, Restraints...............1-33
Ination - Tire Pressure...................................5-62
Instrument Panel
Overview..................................................... 3-4
Instrument Panel (I/P)
Brightness..................................................3-19
Cluster.......................................................3-26
J
Jump Starting.................................................5-42
K
Keyless Entry System....................................... 2-4
Keys............................................................... 2-3
6