Page 140 of 386

2-65
Ashtrays and Cigarette Lighter
Your vehicle has an ashtray and a cigarette lighter
located in the center floor console. To open the
removeable ashtray, flip open the top.
NOTICE:
If you store paper or other things that burn in your
ashtrays, they could be set on fire by cigarettes or
other smoking materials. That could cause a fire
and possibly damage your vehicle. Do not store
papers and other things that burn in your ashtrays.
To use the cigarette lighter, push it in all the way and let
it go. When it's ready, it will pop back out by itself.
NOTICE:
Holding a cigarette lighter in with your hand
while it's heating can make it overload, damaging
the lighter and the heating element. Just push the
lighter all the way in and let it go. When it's
done, it will pop back out by itself.
Sun Visors
To block out glare, you can swing down the visors. You
can also swing them out to block glare from the side.
Accessory Power Outlets
With accessory power outlets, you can plug in
auxiliary electrical equipment such as a cellular
telephone or CB radio.
The accessory power outlets are located on the
passenger's side of the instrument panel.
To use an outlet, pull the cover down. When not using it,
always cover the outlet with the protective cap.
These circuits are protected by a fuse and have
maximum current levels.
NOTICE:
When using the accessory power outlets,
maximum load of any electrical equipment
should not exceed 14 amps. Be sure to turn off
any electrical equipment when not in use.
Leaving electrical equipment on for extended
periods can drain the battery.
Page 142 of 386

2-67
The eight-wire harness contains the following
trailer circuits:
Yellow: Left Stop/Turn Signal
Dark Green: Right Stop/Turn Signal
Brown: Taillamps
White: Ground
Light Green: Back
-up Lamps
Light Blue: CHMSL
Red: Battery Feed
Dark Blue: Trailer Brake
Trailer Connections (C6/C7/C8
Models Only) (If Equipped)
If your vehicle has these trailer connections, they are
located at the rear of the cab for a tractor and at the rear
of the chassis when towing a trailer. There will be an air
connection and an electrical connection.
Be sure that the couplings to the trailer are
made correctly.
Air Connections
If you are not connecting the trailer air line connections
to another piece of equipment, be sure to replace their
protective caps.
Electrical Connections
This system is a seven-wire cable that will connect to
the trailer, supplying power to the trailer's lighting
system. When not in use, it is stored in the trailer
air
-hose storage bracket.
NOTICE:
Starting in 1998, the center pin (also known as
the auxiliary circuit) of the seven
-pin trailer
electrical connector will be wired to provide
continuous power for the trailer anti
-lock brake
systems when the ignition key is in the on
position. Care should be taken to insure that
continuous power on this circuit will not cause
damage to the trailer electrical system.
Consult with the trailer manufacturer for the
proper operation and checking procedures for
the trailer anti
-lock brake systems.
Page 144 of 386
2-69
The main components of your instrument panel are the following:
A. Vents
B. Instrument Panel Cluster
C. Column Shift Lever (If Equipped)
D. Air Brake Control(s) (If Equipped)
E. Auxiliary Gages (If Equipped)
F. Exterior Lamp Control
G. Turn Signal Multifunction Lever
H. Hazard Warning Flashers ButtonI. Auxiliary Switches (If Equipped)
J. Audio System or Storage Area
K. Auxiliary Warning Lights
L. Comfort Controls
M. Instrument Panel Switchbank
N. Air Bag Off Switch (If Equipped)
P. Accessory Power Outlets
Page 153 of 386

2-78 Charging System Indicator Light
The charging system
indicator light may be
located in the instrument
panel cluster, or with the
auxiliary warning lights
in the center of the
instrument panel.
It should come on briefly when you turn on the ignition,
before the engine is running, as a check to show that it
is working.
If it stays on, or comes on while you are driving, have it
checked right away. You could have a loose generator
drive belt or some other problem.
Driving while this light is on will drain your battery. If
you must drive a short distance with the light on, turn
off your radio and other accessories.
Sustained driving with a generator failure could result in
a lack of back
-up braking if the engine quits or the
power steering pump should fail.
Voltmeter
When your engine is
running, the voltmeter
gage, at the right side of
the instrument panel cluster,
shows the charging
system voltage.
Readings in either warning zone indicate a possible
problem in the electrical system.
Readings in the low warning zone may occur when a
large number of electrical accessories are operating in the
vehicle and the engine is left at an idle for an extended
period. This condition is normal since the charging
system may not be able to provide full power at engine
idle. As engine speeds are increased, this condition
should correct itself because higher engine speeds allow
the charging system to create maximum power.
You can only drive a short time on the battery. Be sure
to shut off the radio, the fan or any unnecessary
accessories and have the system serviced.
Page 154 of 386

2-79 Service Transmission Warning Light
(If Equipped)
If your vehicle has an Allison automatic transmission,
certain transmission malfunctions will turn this light on.
This light is located with
the auxiliary warning lights
in the center of the
instrument panel.
If this light comes on while you are driving, do not use
the transmission shift control. Using the transmission
shift control may result in the loss of forward gears. The
computer for the transmission senses a problem and
chooses a gear to stay in so that you can drive the
vehicle in that gear. You may not be able to drive as fast
or back up when this light is on.
NOTICE:
If the service transmission warning light comes
on while you are driving, it is a warning that
making a transmission ªrangeº change could
leave you stranded. The vehicle may not continue
to move if you change gears with the
transmission shift control. The transmission can't
operate in all gears because something is wrong.
Leave the shift control alone and drive directly to
a GM dealer for service. If you can't go in for
service immediately, have the vehicle towed.
Page 336 of 386
6-82
Fuse Block 2
Circuit Breaker Usage
1 Stoplamps
2 Center High Mounted Stop Lamp
3 Parking Lamps
4 Powertrain Control Module
5 Auxiliary Wiring
6 Heater/Air ConditioningCircuit Breaker Usage
7 Hazard Warning Flashers
8 Power Post
9 Courtesy Lamps
10 Warning Lights, Gages
and Indicators
11 Crank
12 Rear Axle
13 Trailer Turn Signals/Hazard
Warning Flashers
14 Radio/Chime
15 Daytime Running Lamps
16 Air Bag System
17 Exterior/Interior Lamps
18 Parking Brake
19 Accessory Power
20 Ignition
21 Sidemarker Lamps
22 Turn Signal/Backup Lamps
23 Transmission
24 Chassis
A Spare
B Spare
Page 342 of 386

6-88 Engine Oil with Filter Capacity
Engine Quarts (Liters)
7.2L** 30.0 (28.4)*
8.1L** 6.5 (6.1)
7.8L** 23.8 (22.5 )
6.6L** 14.6 (13.8)
*Additional oil is required with auxiliary oil filter
systems. Make sure to add enough extra oil to fill the
auxiliary oil filter system. For vehicles equipped with
the LUBERFINER 750
-C, add 14 quarts (13.25 L).
** Check fill level on the oil indicator after initial fill to
make sure it is actually full. Oil level may vary
depending on vehicle option content.
Fuel Tank Capacity
C4/C5 Models Gallons (Liters). . . . . . . . . . . . . . . . .
Standard* 41 (155.2). . . . . . . . . . . . . . . . . . . . . . . .
Optional 40 (151.4). . . . . . . . . . . . . . . . . . . . . . . . . .
Optional 60 (227.1). . . . . . . . . . . . . . . . . . . . . . . . . .
Optional 80 (302.8). . . . . . . . . . . . . . . . . . . . . . . . . .
C6/C7/C8 Models Gallons (Liters). . . . . . . . . . . . . .
Standard 50 (189.2). . . . . . . . . . . . . . . . . . . . . . . . .
Optional 35 (132.4). . . . . . . . . . . . . . . . . . . . . . . . . .
Optional 50 (189.2). . . . . . . . . . . . . . . . . . . . . . . . . .
Optional70 (264.8) . . . . . . . . . . . . . . . . . . . . . . . .
Optional75 (283.8) . . . . . . . . . . . . . . . . . . . . . . . .
Optional& 100 (378.5). . . . . . . . . . . . . . . . . . . . . . .
* One 25
-gallon (94.6 L) tank and one 16-gallon
(60.6 L) tank
Two 35
-gallon (132.4 L) tanks
One 25
-gallon (94.6 L) tank and One 50-gallon
(189.2 L) tank
&Two 50
-gallon (189.2 L) tanks