2002 CHEVROLET C3500 HD air conditioning

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

6-67 Capacities
After refill, the level must be rechecked. See ªCooling
Systemº in the Index.
Engine VIN Quantity
ªVORTECº 8100 G 28.5 quarts (27.0 L)
Engine Oil with Filter
After refill, the level must be rechecked. Add enough
engine oil so that the fluid is within the proper operating
range. See ªEngine Oilº in the Index.
Engine VIN Quantity
ªVORTECº 8100 G 6.6 quarts (6.3 L)
Fuel Tank Capacity
Type Quantity
Front Tank 22.0 U.S. gallons (79 L)
Rear Tank 18.0 U.S. gallons (68 L)
Air Conditioning
Refrigerant Capacity
If you do your own service work, you'll need the proper
service manual. See ªDoing Your Own Service Workº in
the Index for additional information. It is recommended
that service work on your air conditioning system be
performed by a qualified technician.
Air Conditioning
Refrigerant R
-134a 2.0 lbs (0.91kg). . . . . . . . . . . . .
Use Refrigerant Oil, R134a Systems

7-50 Engine Cooling System Inspection
Inspect the hoses and have them replaced if they are
cracked, swollen or deteriorated. Inspect all pipes,
fittings and clamps; replace as needed. Clean the outside
of the radiator and air conditioning condenser. To help
ensure proper operation, a pressure test of the cooling
system and pressure cap is recommended at least once
a year.
Throttle System Inspection
(Gasoline Engine)
Inspect the throttle system for interference or binding,
and for damaged or missing parts. Replace parts as
needed. Replace any components that have high effort
or excessive wear. Do not lubricate accelerator and
cruise control cables.
Brake System Inspection
Inspect the complete system. Inspect brake lines and
hoses for proper hook
-up, binding, leaks, cracks,
chafing, etc. Inspect disc brake pads for wear and rotors
for surface condition. Inspect other brake parts,
including calipers, parking brake, etc. Check parking
brake adjustment. You may need to have your brakes
inspected more often if your driving habits or conditions
result in frequent braking.