Peterbilt 320 Operator's Manual

Quick Table of Contents

PART 1: INTRODUCTION.. ..................................................................... ..........1

PART 2: CAB AND FRAME ACCESS.................................... ............................ 6

PART 3: GETTING TO YOUR ENGINE...... ... ..................................................10

PART 4: CONTROLS AND DISPLAYS............. ....................................... ........15

PART 5: SEAT AND RESTR AINT SYSTEMS.................. ............ ............ ........57

PART 6 : DRIVER’S CHECKLIST.. ...................................... ............................. 69

PART 7: STARTING & OPERATING THE VEHICLE.. .....................................73

PART 8 : MAINTENANCE AND SERVICE.. ................................................... 110

PART 9: VEHICLE IDENTIFICATION NUMBERS.. .......................................196

PART 1 0: CO NSUMER INFORMATION........................................................199

PART 11: SUBJECT INDEX....................................... ....................................202

Other Publications.. ........................................................................................206

California Proposition 65 Warning

• Diesel engine exhaust and some of its constituents are known to the State
of California to cause cancer, birth defects, and other reproductive harm.

• Other chemicals in this vehicle are also known to the State of California to
cause cancer, birth defects or other reproductive harm.

• Battery posts, terminals, and related accessories contain lead and lead com­pounds, chemicals known to the State of California to cause cancer and re­productive harm. Wash hands after handling.

PART1: INTRODUCTION HowToFindWhatYouWant

PART 1: INTRODUCTION

This manual contains useful information for the safe and
efficient operation of your Model 320. It also provides in­formation on maintaining your vehicle in the best condition,
with an outline for performing safety checks and basic pre­ventive maintenance inspections.

We have tried to present the information you’ll need to learn
about your vehicle’s functions, controls, and operation ­and to present it as clearly as possible. We hope you’ll
find this manual easy to use.

There will be times when you need to take this manual out
of your Peterbilt. When you do, please be sure to return it
to the cab when you are finished using it. That way it will
be there when you need it the next time or when you pass
the vehicle on to the next user.

Your Model 320 may not have all the features or options
mentioned in this manual. Therefore, you should pay c are­ful attention to the instructions that pertain to just your ve­hicle. In addition, if your vehicle is equipped with special
equipment or options not discussed in this manual, consult
your dealer or the manufacturer of the equipment.

All information contained in this manual is based on the lat­est production information available at the time of publica­tion. Peterbilt Motors Company reserves the right to make
changes at any time without notice.

HowToFindWhatYouWant

There are several tools built into this manual to help you
find what you need quickly and easily.

First is the Quick Table of Contents. Located at the front of
the manual, this lists the main subjects covered and gives
page numbers where you can find these subjects. Use
the Quick Table of Contents to find information on a large
subject like "Maintenance."

Cross-referenced Citations also help you get the informa­tion you need. If some other part of the manual contains
further information on the subject you are reading about,
we’ll indica te that in a cross-reference like this: (See "
6: DRIVER’S CHECKLIST". You won’t have to go search­ing for more information.

Finally you’ll find a helpful Subject Index. It’s in the back
of the manual and alphabetically lists the subjects covered.

PART

R(08/07) Y53-6015 – 1 –

Additional Sources of Information PART 1: INTRODUCTION

So if you want information on brakes, for example, just look
under Brake in the Subject Index. You’ll find all the pages
listed where brakes or braking are discussed.

A Special Word About Repairs

Your Peterbilt dealer’s service center is the best place to
have your vehicle repaired. You can find Peterbilt dealers
all over the country with the equipment and trained person­nel to get you back on the road quickly - and keep you there.

Your vehicle is a complex machine. Anyone attempting re­pairs on it needs good mechanical training and the proper
tools. If you are sure you have these requirements, then
you can probably perform some repairs yourself. However,
all warranty repairs must be performed by an authorized
Peterbilt service fa cility. If you aren’t an experienced me­chanic, or don’t have the right equipment, please leave all
repairs to an authorized service facility. They are the ones
equipped to do the job safely and correctly.

WARNING! Attempting repair work without suf­ficient training, service manuals, and the proper
tools can be dangerous. You could be injured
or you could make your truck unsafe. Do only
those tasks you are fully qualified to do.

Maintenance Manuals. Ifyoudodecidetodoanycom­plex repair work, you’ll need the Peterbilt Maintenance
manuals. Order them from your authorized dealer. Please
provide your Chassis Serial Number when you order, to be
sure you get the correct manuals for your vehicle. Allow
about four weeks for delivery. There will be a charge for
these manuals.

Final Chassis Bill of Material. A complete, nonillustrated
computer printout listing of the parts used to custom- b uild
your Peterbilt vehicle is available through the Peterbilt
dealer from whom your purchased your veh icle.

WARNING! Modifying your vehicle can make
it unsafe. Some modifications can affect your
truck’s electrical system, stability, or other
important functions. Before modifying your
vehicle, check with your dealer to ma ke s u re it
can be done safely.

Additional Sources of Information

Operator’s manuals are also supplied by the m a nufacturers
of components such as the engine, seats, transmission,
and radio in your Peterbilt. If you are missing any of these
manuals, ask your Peterbilt dealer to supply them.

– 2 – Y53-6015 R(08/07)

PART 1: INTRODUCTION Warnings

Your new Peterbilt also contains a copy of the Truck
Driver’s Handbook, published by the American Trucking
Association. Refer to it for important information on driving
your vehicle. Another place to learn more about trucking is
a local truck driving school. Contact one near you to find
out what kinds of instruction it offers.

Federal and state agencies also have information you can
ask for. The Interstate Commerce Commission can give
you information about regulations governing transportation
across state lines. And various agencies in state govern­ments are sources for regulations which differ from state to
state.

Warnings

We’ve put a number of warning messages in this manual.
They are there for your protection and information. Please
read them and follow them. They can help you to avoid in­jury to yourself and your passengers as well as to prevent
costly damage to your vehicle. We’ve used certain sym­bols and "signal words" to indicate what kind of message is
going to follow. When you see these symbols & words, you
know that you need to pay special attention. Please don’t
ignore any of these signals.

WARNING:

When you see this symbol & word, the message that fol­lows is especially vital. This signals something that can
cause serious injury or death. This message will tell you
what the hazard is, what can happen if you don’t heed the
warning, and how to avoid it. For example:

WARNING! Attempting repair work without suf­ficient training, service manuals, and the proper
tools can be dangerous. You could be injured
or you could make your vehicle unsafe. Do only
those tasks you are fully qualified to do.

CAUTION:

This symbol & word signals something that could damage
your vehicle. You might receive an injury, too. For example:

CAUTION: Continuing to operate a vehicle with
insufficient oil pressure will cause serious en­gine damage.

R(08/07) Y53-6015 – 3 –

Vehicle Safety PART 1: INTRODUCTION

NOTE:

Gives you information we feel you’d like to have. It could
have to do with care of your vehicle or with driving more
efficiently:

NOTE: A cold compressor can cause refrigerant to
liquefyandwarpthevalveplatesorcauseahy­draulic lock. Warm the engine before starting the
air conditioner.

Please take the time to read these messages when you see
them. And remember:

WARNING! Something that could injure you seriously.

CAUTION: Something that could cause injury to you or your
vehicle.

NOTE: Useful information.

Vehicle Safety

Make sure your Peterbilt is in top working condition be­fore heading out on the road—it is the responsible driver’s

duty to do so. Inspect the vehicle according to"
DRIVER’S CHECKLIST".

WARNING! Do not drink and drive. Your re­flexes, perceptions, and judgment can be af­fected by even a small amount of alcohol. You
could have a serious—or even fatal accident—if
you drive after drinking. Please do not drink
and drive or ride with a driver who has been
drinking.

WARNING! The use of alcohol, drugs, and cer­tain medications will seriously impair percep­tion, reactions, and driving ability. These cir­cumstances can substantially increase the risk
of an accident and personal injury.

Please remember, this manual is not a training manual. It
cannot tell you everything you need to know about driv­ing your Peterbilt vehicle. For that you need a good train­ing program or truck driving school. If you have not been
trained, get the proper training before you drive. Only qual­ified drivers should drive this vehicle.

Every new Peterbilt vehicle is designed to conform to all
Federal Motor Vehicle Safety Standards applicable at the

PART 6:

– 4 – Y53-6015 R(08/07)

PART 1: INTRODUCTION Vehicle Safety

time of manufacture. However, even with these safety
features, continued safe and reliable operation depends
greatly upon regular vehicle maintenance. The vehicle

must be operated within the range of its mechanical capa­bilities and the limits of its load ratings. Se e the axle and tire
load rating information located on the driver’s door jamb.

R(08/07) Y53-6015 – 5 –

PART 2: CAB AND FRAME ACCESS

Be careful whenever you get into or out of your vehicle’s
cab. Always maintain at least three points of contact with
your hands on the grab handles and your feet on the steps.

WARNING! Jumping out of the cab or getting
into the cab without proper caution is danger­ous. You could slip and fall, possibly suffering
a serious injury. Keep steps clean. Clean any
fuel, oil, or grease off of the steps before en­tering the cab. Use the steps and grab handles
provided, and always keep at least three points
of contact between your hands and feet and the
truck. Look where you are going.

The following pictures show the best way to enter and exit
a Model 320.

PART 2: CAB AND FRAME ACC ESS

02871

Three points of contact as you begin or finish

– 6 – Y53-6015 R(08/07)

PART 2: CAB AND FRAME ACCESS Door Lock and Keys

02872

Three points of contact as you climb up or down

Three points of contact as you step in or out

02873

Door Lock and Keys

Doors can be locked from the inside by using the lock but­ton. Close the door then push the button down to lo c k.
Doors automatically unlock when you open them from the
inside,andcanbelockedfromtheoutsidewithakeyonly.

R(08/07) Y53-6015 – 7 –

Climbing Onto the Deck Plate PART 2: CAB AND FRAME ACCESS

WARNING! To lessen the chance and/or sever­ity of personal injury in case of an accident, al­ways lock the doors while driving. Along with
using the lap/shoulder belts properly, locking
the doors helps prevent occupants from being
thrown from the vehicle.

To lock or unlock the doors from outside the cab, insert the
key in the lock. Turn the key toward the rear to lock; forward
to unlock.

Climbing Onto the Deck Plate

WARNING!

• You can be hurt if you aren’t careful climb­ing onto and off the deck plate. You can slip
and fall, especially if the surfaces are wet or

icy, or if you step in oil, fuel, or grease. Keep
steps clean. Always maintain at least three
points of contact between your hands and
feet and the steps and deck plate.

• Do not climb onto and off the deck plate– use
steps and grab handle provided. If there is
no deck plate, or if proper steps and grab
handles aren’t provided, don’t climb onto the
area behind the cab. Peterbilt did not intend
for the area to be a step if handrails or proper
steps are not provided.

NOTE: Any alteration (adding bulkheads, head­ache racks, tool boxes, etc.) that affects the uti­lization of grab handles, deck plates, or frame
access steps installed by Peterbilt must comply
with FMCSR 399.

– 8 – Y53-6015 R(08/07)

PART 2: CAB AND FRAME ACCESS Front Cab Guard/Ladder

Front Cab Guard/Ladder

The optional front cab guard/ladder is used on front-load­ing refuse vehicles to protect the cab from damage and to
stand on in order to remove debris from above the cab.

0001

WARNING!

• Do not climb on the cab roof. The cab roof
is not a slip-resistant surface and is not
equipped with handholds. A slip and fall
could cause serious injury.

• Do not step or stand on the top rung of the
ladder. This is not a step; it is meant to used
only as a handhold. You could slip or fall and
injureyourselfifyouuseitasastep.

R(08/07) Y53-6015 – 9 –

Cab Tilting PART 3: GETTING TO YOUR ENGINE

PART 3: GETTING TO YOUR ENGINE

Cab Tilting

WARNING! You can be seriously injured by the
cab if you do not follow safety precautions.
Whenever you raise or lower the cab, or when
you work under the cab, please remember the
following safety rules:

• Be sure no one is under the front of the cab.
Whether you are raising or lowering the cab,
KEEP CLEAR.

• Never work under a raised cab unless it is
properly supported. This means use an over­headhoistofsufficient capacity to support
the cab safely. Never prop the cab up instead
of using a hoist. The prop could fail and let
the cab fall on you or anyone else working
under the cab.

• Always be sure the safety latch is engaged
when you or anyone else works under the
cab.

– 10 – Y53-6015 R(08/07)

• Perform work only when the cab is in the me­chanically locked position or in the full tilt po­sition.

• When your cab’s hydraulic system needs
service or repair:

• Have maintenance an d repair don e o nly by

someone qualified in hydraulic systems.

• Besurenoonetriestobleedthesystem

with the cab raised. This will defeat the
safety system. The cab can fall and crush
anyone under it.

• Do not tamper with any part of the cab tilt

cylinders, including removing the velocity
fuses. To do so will defeat their purpose.
The cab could fall and crush anyone under
it. If you have any need for repair involving
the velocity fuses, have a qualified truck
mechanic do the work.

NOTE: In case of oil loss in the system or a lockup
in the tilt cylinders, refer to the maintenance manual
for repair instructions.

PART 3: GETTING TO YOUR ENGINE Raising the Cab

Raising the Cab

An independent hydraulic system raises and lowers the
cab. A positive, dual-locking device ensures safety and
eliminates danger of mishaps while driving.

WARNING! Do not get any part of your body un­der an unsecured cab. It could cause a serious
or fatal accident. The cab could fall and crush
you. Always ensure the locking bar is fully en­gaged before getting under the cab, or before
letting anyone else get under it (see following
instructions on using the locking bar).

WARNING!

• Raising the cab with heavy objects in the cab
can cause serious damage to the cab tilting
mechanism and cab. Before raising the cab,
remove heavy items su ch as tire chai n s and
tools. Remove or stow securely any loose
items. And shut the doors tightly.

• Straighten the front wheels before tilting the
cab or cab/tire damage could occur.

The following cab tilting instructions are labelled and in­stalled on the base of the companion seat:

1. Park the vehicle on a level surface.

2. Apply the parking brake.

3. Make sure the shift lever is in Neutral. This will prevent
the shift lever from getting caught on the cab during
tilting operations.

4. Secure or remove all loose items in the cab. Close all
doors.

5. Check the clearance above and ahead of the cab. En­sure there will be enough room to clear roof antennae
when you tilt the cab. Check for obs tructions overhead
(branches, power lines, lights, etc.) and in front (walls,
work benches, other vehicles, etc.).

6. Place the control valve handle in the "Raise" position.

R(08/07) Y53-6015 – 11 –

Raising the Cab PART 3: GETTING TO YOUR ENGINE

02874

Handle in "Raise" Position

02875

Locking Bar in Anchored Position

7. Attach pump handle to the pump and pump to raise the
cab (the latch hooks will release automatically when
pump is actuated). Pump until the locking bar can
be positioned on the anchor mounted below the right-

8. Place the control valve handle in the “Lower” position
and allow the cab to settle down slightly on the locking
bar.

hand cab suppo rt as shown in the next illustration.

– 12 – Y53-6015 R(08/07)

PART 3: GETTING TO YOUR ENGINE Lowering the Cab

02876

Handle in "Lower" Position

02877

CabinFullTiltPosition

Lowering the Cab

1. Place the control valve handle in the "Raise" position
and pump until the locking bar can be removed from
the anchor and fastened in its stored position.

R(08/07) Y53-6015 – 13 –

Lowering the Cab PART 3: GETTING TO YOUR ENGINE

02878

Locking Bar In Stored Position

Upper and Lower Rear Cab Mount

02879

3. Allow at least 20 seconds after the cab touches down

CAUTION: Do not try to pump the cab down
or hold it down with hydraulic force. If you
do, cab damage will occur.

2. Place the control valve handle in the "Lower" position.
The cab should settle down on the rear mounts.

for the full spring force to develop in the latch hooks in
the rear mounts.

4. Remove the pump handle and store in the cab.

5. Visually inspect the cab latch hooks to ensure they are
closed.

6. Ensure that the control valve handle is in the “Lower”
position when operating the vehicle.

– 14 – Y53-6015 R(08/07)

PART 4: CONTROLS AND DISPLAYS Your Instrument Panel

PART 4: CONTROLS AND DISP LAYS

This part explains the location of the various features on
your vehicle and describes their function. For inform at ion
on using these features in driving, see the paragraphs that
follow.

Your Instrument Panel

Please remember that each Peterbilt is custom-made. Your
instrument panel may not look exactly like the one in the
illustrations on the pages that follow.

We have tried to describe all the most common features
and controls available, so your vehicle may not have some
of the ones that appear in this section. You can pick out the
parts that apply to you and read them to be fully informed
on how your particular vehicle operates.

R(08/07) Y53-6015 – 15 –

Your Instrument Panel PART 4: CONTROLS AND DISPLAYS

LEFT SIDE

0002

Typical Instruments & C ontrols: Left-Hand Drive Station

1. Turn Signal/Hazard Flasher

2. Accelerator Pedal

3. Brake Pedal

4. High Beam Switch

5. Clutch Pedal

6. Ignition Key Switch

7. Clearance Lamps Switch

8. SMC Select/Reset Switch

9. Headlight Switch

10. Voltmeter

11. Engine Oil Pressure

12. Engine Coolant Temperature

13. Tachometer

14. LED Warning Light Ba r

15. Panel Light Knob

16. Speedometer w/ Message
Center (SMC)

17. Primary Air Pressure

18. Fuel

19. Transmission Oil Temp.

20. Secondary Air Pressure

21. Gearshift or Shift Selector

22. Heater Control Panel

23. Cigar Lighter

24. Interaxle Differential Lock

25. Parking Brake Valve

26. Windshield Wiper Valves

27. Windshield Washer Switch

– 16 – Y53-6015 R(08/07)

PART 4: CONTROLS AND DISPLAYS Warning Alarms

RIGHT SIDE

0003

Typical Instruments & Controls: Right-Hand Drive Station

1. Turn Signal/Hazard Flasher

2. Transmission Controls

3. Parking Brake Valve

4. Horn Button

5. Windshield Washer
Reservoir

6. Working Brake Switch

7. Warning Lights

8. Headlight Switch

9. Secondary Air Pressure

10. Starter Switch

11. Stop Switch

12. Prim a ry Air Pressure

13. Engine Oil Pressure

14. Safety Chain

15. Bra ke Pedal

16. Accelerator Pedal

Warning Alarms

A warning alarm occurs when some condition in the vehicle
requires attention. A warning alarm cannot be turned off or
manually reset. Once triggered, an alarm w ill continue to
exist until the unacceptable condition or fault in a function
is corrected.

R(08/07) Y53-6015 – 17 –

Warning Alarms PART 4: CONTROLS AND DISPLAYS

NOTE:Inadditiontothewarningmessagesmen­tioned in this part - if any of the following conditions
occur after startup and self-test, the multiplex in­strumentation system should be serviced

• The speedometer-message center (SMC)
pointer exhibits windshield wipe r-like motion
and the display reads NO DATA

• One or more gauge pointers exhibit wiper-like
motion.

• A gauge pointer stays at zero with its red light
flashing.

• A gauge pointer goes to and remains at a 2:00
position with its red light on steady.

A multiple x instrumentation system alarm can be sign a lled
by up to four indicators:

• A warning message will appear on the SMC display
(all alarms).

• The light-emitting diode (LED) warning light in the
function’s gauge will go on (all alarms except ABS
and multiplex instrumentation system faults).

• An audible alarm will sound.

• A light bar icon will light.

NOTE:

• Warning messages from system alarms with an
audible alarm can be temporarily overridden by
pressing the Reset switch. You can then press
the Select switch to scroll through other functions

- but the message will reappear in 60 seconds.
The audible alarm will always be on.

• Warning messages from system alarms without
an audible alarm can be dismissed by pressing
the Reset switch. To view dismissed active mes­sages, turn the ignition off and back on.

An alarm’s warning message on the SMC will preemp t all
other SMC displays until the condition that is causing the
alarm is corrected. T his preemption includes other warning
messages from earlier alarms - and some of these alarms
may not have other indicators. Therefore, it is very impor­tant that you check the SMC to be aware of all alarm con­ditions that may exist in your vehicle’s systems - especially
during the start-up procedure. A summary of alarms and
indicators is at the end of this part. Follow this procedure
to check all SMC warning messages.

1. Obse rve the first message displayed after the SMC
comes on.

– 18 – Y53-6015 R(08/07)

PART 4: CONTROLS AND DISPLAYS Warning Alarms

• If the odometer is displayed, continue with the
start-up procedure.

• If a warning m essage is displayed instead of the
odometer, it is being generated by the multiplex in­strumentation syste m:

– Look in the alarm summary to identify the gauge.

– Go to the description of that gauge in"

PART 4:
CONTROLS AND DISPLAYS" and take the ac­tions indicated to correct the condition.

2. Continue to check and act on all warning messages
until the odometer is displayed.

Multiplex Instrumentation System Alarm Summary

Display Activation

Condition

H2O TMP Coolant

temp. is high

IM CAL System Fault

IM CFG System Fault

Gauge LED

Engine Water

Temperature

None

None

Buzz Deactivation

yes

no

no

Display

H2OT OK

None

None

Display Activation

IM DIAG System Fault

IM LIN

IM SLFT System Fault

LOW
AIR1

LOW
AIR2

LO

WATER

NO DATA System Fault

ODO ERR System Fault

OIL TMP

OIL PRES

Condition

System Fault

Low air

pressure in

air tank #1

Low air

pressure in

air tank #2

Coolant level

is low

Engine oil

temperature

is high

Engine oil

pressure is

low

Gauge LED

None

None

None

Primary air

pressure

Secondary

air pressure

Engine Water

Level

None

None

Engine Oil

Temperature

Engine Oil

Pressure

Buzz Deactivation

no

no

no

yes

yes

yes

no

no

yes

yes

Display

None

None

None

AIR1 OK

AIR2 OK

WATER O K

None

None

OILT OK

OIL OK

R(08/07) Y53-6015 – 19 –

Turn Signal and Indicator Lights PART 4: CONTROLS AND DISPLAYS

Display Activation

SMC
MEM

TRANTMP Main

Condition

System Fault

transmission

oil

temperature

is high

Gauge LED

None

Main

Transmission

Oil

Temperature

Buzz Deactivation

no

yes

Display

None

TRAN OK

Steering Column-Mounted Controls

Turn Signal and Indicator L igh ts

02882

Turn Signal

The turn signal body is mounted on the left side of the steer­ing column, below the steering wheel.

• At a right-hand drive station, the turn signal body is
mounted on a stub shaft under the dash behind the
steering wheel.

– 20 – Y53-6015 R(08/07)

PART 4: CONTROLS AND DISPLAYS High Beam Headlights

other vehicle could run into you if you do not set

NOTE: The ignition key must be turned to ON for
the signal/switch to operate.

To operate either signal, move the lever in the direction of
the turn.

Of course, in normal stopping in traffic, such as at a stop
light, you do not use your flashers.

your flashers. Always move the vehicle a safe
distance off the road when stalled or stopped
for repairs

Hazard Flasher

The four-way Hazard Flasher switch is on the turn signal
body, just below the turn signal lever.

• At a right-hand drive station, the switch is above the
lever.

The flasher will operate with the key switch in the on or off
position. Pull it out to activate the system. All turn signals
will flash at once. To turn it off, move the turn signal lever
up or down.

Use your hazard flasher whenever you are off the road or
on the side of the road, or in a potentially hazardous situa­tion.

WARNING! Use your Hazard Flasher Warning
System any time you have to stop off the road or
on the side of the road, day or night. A hard to
see vehicle can result in an injury accident. An-

High Beam Headlights

All Model 320 vehicles c o me equipped with a co mbina­tion turn signal and high beam / low beam switch that is
mounted to the steering column. To switch your headlights,
push and release the button on the end of the turn sig­nal lever. The high beam indicator light is displayed in the
tachometer face

WARNING! Your disabled vehicle can be dan­gerous for you and others. The hot exhaust sys­tem could ignite dry grass, spilled fuel, or other
substances. Do not park or operate your vehi­cle w here the exhaust system could contact dry
grass, brush, spilled fuel, or any other material
that could cause a fire.

R(08/07) Y53-6015 – 21 –

Trailer Brake Hand Valve PART 4: CONTROLS AND DISPLAYS

Trailer Brake Hand Valve

02885

02884

High Beam Headlight Switch Button

If your vehicle is a tractor, it will be equipped with a trailer
brake hand valve. This hand valve provides air pressure to
apply the trailer brakes only. It operates independently of
the foot treadle valve.

To operate the trailer brake hand valve: Pull down on
the lever on the right side of the steering column, below
the steering wheel.

Trailer B rak e Hand Valve

– 22 – Y53-6015 R(08/07)

PART 4: CONTROLS AND DISPLAYS Electric Horn

WARNING! It is dangerous to use air-applied
trailer brakes for parking or holding a vehicle.
Air system pressure can bleed down and re­lease the brakes. You could have a vehicle roll­away resulting in an accident. You or others
could be badly injured. Always apply the park­ing brakes for parking or holding your vehicle
on grade.

NOTE: The traile r brake is not to be use d as the
main means of braking. To use this brake frequently
instead of using the foot brake will wear out the
trailer brake sooner.

See "

Parking Brakes and Their Use" for more complete
information on when and how to use your trailer brake. Or
see the Index, under Brake.

Electric Horn Button

Air Horn

Your Pe te rbilt has an a ir horn in addition to an electric horn.

02886

Control the air horn by pulling on the lanyard exten ding from

Electric Horn

the overhead header panel.

Your vehicle has an electric horn. To sound the horn, press
on the button in the center of the steering wheel. At a right­hand stand-up drive station, the horn button is located on
the dash panel to the right of the steering wheel.

R(08/07) Y53-6015 – 23 –

Ignition Switch PART 4: CONTROLS AND DISPLAYS

Dash-Mounted Features

Keys and Locks

The same key operates the ignition and opens the doors.
Frame-mounted tool box locks and locking fuel tank caps
each have individual keys.

Ignition Switch

Your ignition switch has four positions:

• OFF: In this (center) position, all accessories are off
(except those listed below), and you can remove the
key:

– Brake lights

– Panel lights

– Tail lights

– Cigarette lighter

– Clearance lamps

–Horn

– Headlights

– R adio station memory

– Emergency hazard flasher
– A uxiliary power
– Dome light

This is the key position that w ill stop the engine from the
left-hand drive stat ion.

• ACC (Accessory): In this position (to the left of center),
you can play the radio or use other accessories, but
your engine won’t start.

• ON: In this position (to the right of center), all circuits
except the cranking circuit are energiz ed. The warn­ing light bar and the multiplex instrument system will
begin its start-up (self-test) p rocedure. In this switch
position, the key cannot be removed.

• START: When the key is turned and held in this posi­tion (full right of center), the starter motor will engage
and crank the engine. Also, it is not uncommon for
some or all of the multiplex instrument system gauges
to begin their start-up procedure again. This is due to
the drop in the system voltage during engine cranking.

NOTE: The multiplex instrument system start-up
(self-test) procedure is described in "
STARTING & OPERATING THE VEHICLE" of this
manual.

PART 7:

– 24 – Y53-6015 R(08/07)

PART 4: CONTROLS AND DISPLAYS Manual Override for Engine Shutdown

Starter Button

02887

With the ignition switch ON, pushing this button at the right­hand drive station will perform the same function as turning
the key to the START position at the left-hand drive station.

Stop Button

02888

Pushing this button at the right-hand drive station stops the
engine.

Manual Override for Engine Shutdown

03020

On vehicles with an engine shutdown, you will have to hold
the manual throw switch in the UP position until normal
engine pressures are reached. If you have one of these
systems, a label on the control panel will say so.

For detailed s tarting procedures, see the Index, under
Starting And Operating.

R(08/07) Y53-6015 – 25 –

Panel Light Knob PART 4: CONTROLS AND DISPLAYS

Headlights

02890

The headlights are controlled by the control panel
switch(es) showing the above symbol. When the head­lights are ON, the dash lights, side, and tail lamps are also
on.

WARNING! Do not use daytime running lights
(DRL) during periods of darkness or reduced
visibility. Do not use DRL as a substitute for
headlights or other lights during operations that
require lighting of your vehicle. Doing so could
lead to an injury accident.

NOTE: On vehicles equipped with daytime running
lights (DRL), the high-beam headlamps go on auto­matically at reduced brightness if the engine is run­ning and the headlamp s witch is turned off. The

daytime running lights are turned off automatically
while the parking brake is engaged. If the headlamp
switch is turned on, the DRL system is overridden
& headlamps operate normally.

Panel Light Knob

02891

The Panel Light Knob lets you vary the brightness of your
instrument panel lights.

To Operate Your Panel Light Knob:

1. Turn on either the headlights, c learance lights, or fog /
driving lights.

2. To brighten the instrument panel lights, turn the knob
clockwise.

3. To dim the instrument lights or to turn them off, turn the
knob counterclockwise.

– 26 – Y53-6015 R(08/07)