2002 CHEVROLET C3500 HD relay

6-62
Fuse/Circuit
BreakerUsage
1 Stop/TCC Switch, Buzzer,
Center High Mounted Stop Lamp,
Hazard Lamps, Stoplamps
2 Not Used
3 Courtesy Lamps, Cargo Lamp,
Glove Box Lamp, Dome/Reading
Lamps, Vanity Mirrors
4 Instrument Cluster, DRL Relay,
Lamp Switch, Keyless Entry,
Low Coolant Module,
Illuminated Entry Module,
DRAC (Diesel Engine)
5 Not Used
6 Cruise Control
7 Auxiliary Power Outlet
8 Crank

6-63
Fuse/Circuit
BreakerUsage
9 License Lamp, Parking Lamps,
Taillamps, Roof Marker
Lamps, Front Sidemarkers,
Door Switch Illumination,
Headlamp Switch Illumination
10 Not Used
11 Wiper Motor, Washer Pump
12 A/C, A/C Blower,
High Blower Relay
13 Power Amp, Cigarette Lighter,
Door Lock Relay
14 Cluster, Comfort Controls,
Instrument Switches, Radio
Illumination, Chime Module
15 DRL Relay
16 Front and Rear Turn Signals,
Back
-Up LampsFuse/Circuit
BreakerUsage
17 Radio (Ignition)
18 4WAL/VCM, Antilock Braking
System, Cruise Control
19 Radio (Battery)
20 PRNDL, Automatic Transmission,
Speedometer, Check Gages
Warning Light
21 Security/Steering
22 Not Used
23 Not Used
24 TP2 Relay (Gasoline Engine)
A Power Door Lock, Keyless
Entry Module
B Power Windows

6-64
Underhood Fuse Block
The underhood fuse block is located in the rear of the
engine compartment near the brake fluid reservoir.
See ªEngine Compartment Overviewº in the Index
for more information on location. Move the retainer
clips for the cover to access the fuse block.
You can remove fuses with a fuse extractor which is
mounted to the interior fuse block. 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.
Name Usage
Starter Relay Starter
A/C Relay Air Conditioning
Fuel Pump Relay Fuel Pump
Brake Lamp
RelayBrake Lamp
Blank Not Used

6-65
Name Usage
Horn Relay Horn
ECM
-B Fuel Pump, PCM/VCM
RR DEFOG Not Used
IGN
-E A/C Compressor Relay,
Dual Tanks
Blank Not Used
Blank Not Used
Blank Not Used
HORN Horn, Underhood Lamps
AUX FAN Not Used
ECM
-1 Injectors, PCM/VCM, Fuel
Solenoid (Diesel Engine) Fuel
Control Module (Diesel Engine)
HTD ST
-FR Not Used
Blank Not Used
Blank Not Used
A/C Air Conditioning
PTO PTO RelayName Usage
ENG
-1 Ignition Switch, Exhaust Gas
Recirculation, Canister Purge,
EVRV Idle Coast Solenoid, MAF,
Heated O
2, Fuel Heater (Diesel
Engine), Water Sensor (Diesel
Engine), Boost Solenoid (Diesel
Engine), EPR (Diesel Engine)
HTD ST
-RR Not Used
Blank Not Used
Diode Not Used
LIGHTING Headlamp and Panel Dimmer
Switch, Fog and Courtesy Fuses
BATT Battery, Fuse Block Busbar
IGN A Ignition Switch
IGN B Ignition Switch
ABS Anti
-Lock Brake Module
BLOWER High Blower Relay
STOP/HAZ Stoplamps
HEATED
SEATSNot Used