1998 Chevrolet C3500 HD 7.4 J, StandardFACTORY OEM SERVICE PROCEDURE

Component Locations

NOTE: Component location illustrations are not available at time of publication.
COMPONENT LOCATIONS (VIN J)

Component Location
A/C Compressor Clutch Cycling Switch On Top Of Accumulator, Right Rear Of Engine Compartment
A/C Compressor Clutch Relay In Power Distribution Box At Left Rear Of Engine Compartment
A/C High Pressure Cut-Out Switch On Rear Of A/C Compressor
A/C Low Pressure Cut-Off Switch On Top Of A/C Compressor, In High Pressure Line
Air Injection Reaction Relay In Power Distribution Box At Left Rear Of Engine Compartment
Auxiliary Cooling Fan Relay Left Rear Side Of Engine Compartment
Camshaft Position (CMP) Sensor In Distributor
Crankshaft Position (CKP) Sensor Lower Right Front Of Engine Block, Near Crankshaft
Cruise Control Module Left Rear Side Of Engine Compartment, On Bulkhead
Data Link Connector (DLC) Under Left Side Of Instrument Panel
Distributor Top Of Engine, Near Bulkhead
EGR Valve Left Center Of Engine, Above Valve Cover
Engine Coolant Temperature (ECT) Sensor On Left Cylinder Head, Near No. 1 Spark Plug
EVAP Canister Purge Solenoid Right Center On Intake Manifold, Near MAP Sensor
EVAP Canister Vent Near Master Cylinder, At Left Front Wheelwell
EVAP Purge Solenoid Vacuum Switch Right Rear Top Of Engine, Right Of Purge Solenoid
Fuel Injectors On Intake Manifold
Fuel Pump Oil Pressure Switch Rear Center Of Engine, Behind Distributor
Fuel Pump Prime Connector At Instrument Panel Harness, Near Instrument Panel Fuse Box
Fuel Pump Relay In Power Distribution Box
Fuel Tank Pressure Sensor In Fuel Tank
Heater & A/C Control Module Center Of Instrument Panel, At Heater Control
Idle Air Control (IAC) Valve Right Rear Of Throttle Body
Ignition Coil Right Rear Of Engine
Ignition Control Module Right Rear Of Engine
Intake Air Temperature (IAT) Sensor On Air Intake Duct
Knock Sensor Right Side Of Engine, Below Exhaust Manifold, Forward Of Starter
Manifold Absolute Pressure (MAP) Sensor Top Center Of Intake Manifold, Near Fuel Injectors
Mass Airflow (MAF) Sensor On Air Intake Duct, Near Air Filter
Oxygen Sensors In Exhaust Pipe, At Front & Rear Of Catalytic Converter
Power Distribution Box Left Rear Of Engine Compartment, On Wheelwell
Power Steering Control Module Under Center Of Instrument Panel
Throttle Position (TP) Sensor On Side Of Throttle Body
Transfer Case Relay Right Rear Of Engine Compartment, Near Center Of Cowl
Vehicle Control Module (VCM) In Engine Compartment, Near Master Cylinder, At Left Front Wheelwell
Vehicle Speed Sensor Left Rear Side Of Transmission, (Left Side Of Transfer Case On Vehicles With 4WD)
Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.

Rather have a pro handle this?

A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.

Comes to youSame-day available12-month warranty
Get a Free Quote

No obligation. See pricing before you book.