Page 323 of 497
4-95 Auxiliary Battery (If Equipped)
The auxiliary battery provision can be used to supply
electrical power to additional equipment that you may
choose to add, such as a slide
-in camper.
If your vehicle has this
provision, this relay will be
located on the passenger's
side of the vehicle, next to
the auxiliary battery.
When using this provision, connection should only be
made to the upper stud (A) of the relay. Do not make
connections to the lower stud (B) of the relay.The auxiliary battery circuit is protected by a megafuse
located behind the auxiliary battery.
Be sure to follow the proper installation instructions 
that are included with any electrical equipment that 
you install.
NOTICE:
When using the auxiliary battery provision, the
electrical load must not exceed 30 amps. Always
turn off any electrical equipment when not in use.
Leaving electrical equipment on for extended
periods will drain your battery. 
         
        
        
     
        
        Page 444 of 497
6-79
Fuse Usage
CRUISE Cruise Control, Instrument 
Panel Cluster
4WD Four
-Wheel Drive System,
Auxiliary Battery
TURN Exterior Lamps, Turn Signals,
Hazard Lamps
RR WIPER Not Used
WS WPR Windshield Wipers
SEO IGN Special Equipment Option,
Ignition, Manual Selectable Ride
ILLUM Interior Lamps
IGN 1 Ignition, Instrument Panel
SEO ACCY Special Equipment Option
Accessory, Cellular Telephone
L BODY Retained Accessory Power Relay
CRANK Starting SystemFuse Usage
AIR BAG Air Bag
MIR/LOCK Power Mirrors, Power Door Locks
SEAT Power Seat Circuit Breaker
DR LOCK Power Door Locks
RAP #1 Retained Accessory Power Relay
LOCK Power Door Locks
INT PRK Interior Lamps
UNLOCK Power Door Locks
DRV UNLOCK Power Door Lock Relay
L DOOR Power Door Lock Relay
PWR WDO Power Window Circuit Breaker
RDO 1 Audio System
RAP #2 Not Used
LOCK Power Door Lock Relay
UNLOCK Power Door Lock Relay 
         
        
        
     
        
        Page 445 of 497
6-80
Center Instrument Panel Fuse Block
The center instrument panel utility block is located
underneath the instrument panel, to the left of the
steering column.Relay Name Usage
SEO Special Equipment Option
HTD ST Heated Seats
SPARE 4 Not Used
VANITY Headliner Wiring
TRAILER Trailer Brake Wiring
PWR ST Power Seats
SPARE 5 Not Used
CLUTCH Manual Transmission 
Clutch Switch
UPF Upfitter
PARK LAMP Parking Lamps (Relay)
FRT PRK EXPT Not Used (Fuse)
SL RIDE Manual Selectable Ride Switch
SPARE 2 Not Used
RR PRK LP Not Used (Relay)
RR FOG LP Not Used (Relay)
SPARE 3 Not Used
INADV PWR Interior Lights Feed
CTSY LP Courtesy Lamps
CEL PHONE Cellular Telephone Wiring 
         
        
        
     
        
        Page 446 of 497
6-81
Underhood Fuse BlockThe underhood fuse block in the engine compartment on
the driver's side of the vehicle near the battery. Lift the
cover for access to the fuse/relay block.
Once you remove the cover, you will see some fuses to
the top right of the fuse/relay block. These are spare
fuses and can be used accordingly.
You can remove fuses with a fuse extractor. The fuse
extractor is located in the underhood electrical center. To
remove fuses if you don't have a fuse extractor, hold the
end of the fuse between your thumb and index finger
and pull straight out.
See ªEngine Compartment Overviewº in the Index for
more information on its location. 
         
        
        
     
        
        Page 448 of 497

6-83
*1 INJ B--Gasoline Engine and Diesel Engine.
 *2 ECM I
--Gasoline Engine; ECMRPV--Diesel Engine.
*3 02 A
--Gasoline Engine; FUEL HT--Diesel Engine. 
*4 02 B
--Gasoline Engine; ECM I--Diesel Engine.
Fuse Usage
GLOW PLUG Diesel Glow Plugs and Intake 
Air Heater
CUST FEED Gasoline Accessory Power
STUD #1 Accessory Power/Trailer 
Wiring Feed
ABS Anti
-Lock Brakes
IGN A Ignition Switch
AIR A.I.R. System
RAP #1 Retained Accessory Power, Power
Mirrors, Power Door Locks,
Power Seat(s)
IGN B Ignition Switch
RAP #2 Not Used
STUD #2 Accessory Power/Trailer Wiring
Brake Feed
SPARE Spare FuseFuse Usage
TRL R TRN Right Turn Signal Trailer Wiring
TRL L TRN Left Turn Signal Trailer Wiring
IGN 1 Ignition, Fuel Controls (Relay)
INJ B Ignition, Fuel Controls
STARTER Starter (Relay)
PARK LP Parking Lamps
FRT HVAC Climate Control System
STOP LP Exterior Lamps, Stoplamps
ECM I PCM
ECMRPV Fuel Controls, ECM
CHMSL Center High Mounted Stoplamp
VEH STOP Stoplamps, Cruise Control
TRL B/U Backup Lamps Trailer Wiring
INJ A Fuel Controls, Ignition
RR HVAC Not Used
VEH B/U Vehicle Backup Lamps
ENG 1 Engine Controls, Canister Purge,
Fuel System
ETC Electronic Throttle Control
IGN E A/C Compressor Relay, Rear
Window Defogger, Daytime
Running Lamps, A.I.R. System 
         
        
        
     
        
        Page 449 of 497

6-84
Fuse Usage
B/U LP Backup Lamps, Automatic
Transmission Shift Lock 
Control System
ATC Automatic Transfer Case
RR DEFOG Rear Window Defogger, 
Heated Mirrors (Relay)
RR PRK Right Rear Parking Lamps
ECM B PCM
F/PMP Fuel Pump (Relay)
O2 A Oxygen Sensors
FUEL HT Fuel Heater, Glow Plug and Intake
Heater Controls
O2 B Oxygen Sensors
LR PRK Left Rear Parking Lamps
RR DEFOG Rear Window Defogger, 
Heated Mirrors
HDLP Headlamps (Relay)
TRL PRK Parking Lamps Trailer Wiring
RT HDLP Right Headlamps
DRL Daytime Running Lamps (Relay)
HTD MIR Heated MirrorsFuse Usage
LT HDLP Left Headlamps
A/C Air Conditioning
AUX PWR Cigarette Lighter, Auxiliary 
Power Outlets
SEO 2 Special Equipment Option Power,
Power Seats, Aux Roof Mnt Lamp
SEO 1 Special Equipment Option Power,
Aux Roof Mnt Lamp, Cell 
Phone, OnStar
DRL Daytime Running Lamps
A/C A/C (Relay)
FOG LP Fog Lamps
FOG LP Fog Lamps (Relay)
RADIO Audio System, Instrument Cluster,
Climate Control System
CIGAR Cigarette Lighter, Auxiliary 
Power Outlets
RT TURN Right Turn Signals
BTSI Automatic Transmission Shift
Lock Control System
LT TURN Left Turn Signals
FR PRK Front Parking Lamps, 
Sidemarker Lamps 
         
        
        
     
        
        Page 450 of 497
6-85
Fuse Usage
W/W PMP Windshield Washer Pump
HORN Horn (Relay)
IGN C Ignition Switch, Fuel Pump,
PRND321 Display, Crank
RDO AMP Not Used
HAZ LP Exterior Lamps, Hazard Lamps
EXP LPS Not Used
HORN Horn
CTSY LP Interior Lamps
RR WPR Not Used
TBC Body Control Module, Remote
Keyless Entry, Headlamps
Replacement Bulbs
Lamps  Quantity  Number
Low
-Beam Headlamps2 9006
High
-Beam
Headlamps2 9005
Daytime Running
Lamps (DRL)2 4157KLamps  Quantity  Number
Front Roof 
Marker Lamps5 194
Front Parking and 
Turn Lamp2 3157 A
Rear Marker Lamp,
Taillamp and 
Stop Lamp2 3157
Taillamp and 
Stop Lamp**2 1157
Rear Turn Lamp 2 3157
Rear Turn Lamp ** 2 1156
Back
-up Lamp2 3157
Back
-up Lamp **2 1156
Center High
-Mounted
Stoplamp2 912
Cargo Lamp 2 912
Fender Marker Lamps 4 194
* For any bulb not listed here, contact your dealer.
** Chassis Cab Models