QuestionHow do i change out a heater core on a 1996 chevy blazer
AnswerHello Philip, This job is not for someone who doesn't want to take a dash apart. You need to remove the complete dash assembly.Here are the steps...
Document ID# 305815 1998 Chevrolet/Geo Blazer - 4WD
Instrument Panel (I/P) Carrier Replacement
Removal Procedure
1. On vehicles equipped with a manual transmission, remove the shift lever.
2. On vehicles equipped with an automatic transmission, perform the following steps:
A. Apply the park brake.
B. Insert the ignition key and turn the ignition switch to the RUN position.
C. Depress the brake pedal and shift the transmission to the 1 position.
D. Turn the ignition switch to the OFF position.
Caution: Before servicing any electrical component, the ignition key must be in the OFF or LOCK position and all electrical loads must be OFF, unless instructed otherwise in these procedures. If a tool or equipment could easily come in contact with a live exposed electrical terminal, also disconnect the negative battery cable. Failure to follow these precautions may cause personal injury and/or damage to the vehicle or its components.
3. Disconnect the battery negative cable.
4. Remove the left sound insulator. Refer to Closeout/Insulator Panel Replacement - Left .
5. Remove the right instrument panel sound insulator. Refer to Closeout/Insulator Panel Replacement - Right .
6. If the vehicle is equipped with a multiple CD changer located in the center console, remove the center console. Refer to Console Replacement - Front Floor .
7. Remove the center sound insulator. Refer to Closeout/Insulator Panel Replacement - Center .
8. Remove the lower left instrument panel mounting bolt.
9. Remove and retain the instrument panel storage compartment. Refer to Door Replacement - Instrument Panel (I/P) Compartment .
10. Remove the lower right instrument panel mounting bolt.
11. Remove and retain the left and right speakers and the speaker grilles. Refer to Speaker Replacement - Front in Entertainment.
12. Use a flat-bladed tool in order to remove the windshield defroster grille. Retain the grille and sunload sensor for use on the next IP carrier.
13. If equipped with a sun load temperature sensor, twist the sensor ¼ turn counterclockwise in order to disengage.
14. Disconnect the brown electrical connection from the body control module (BCM).
15. Disconnect the purple electrical connection from the body control module (BCM).
16. Remove the knee bolster. Refer to Knee Bolster Replacement .
17. Remove and retain the instrument cluster. Refer to Instrument Panel Cluster (IPC) Replacement .
18. Remove and retain the radio. Refer to Radio Replacement in Entertainment.
19. Remove the HVAC control assembly. Refer to the appropriate procedure:
o Control Assembly Replacement in Heating and Ventilation (Non-A/C)
o Control Assembly Replacement in HVAC Systems with A/C - Manual
o Control Assembly Replacement in HVAC Systems with A/C - Automatic
Caution: This vehicle is equipped with a Supplemental Inflatable Restraint (SIR) System. Failure to follow the correct procedure could cause the following conditions:
o Air bag deployment
o Personal injury
o Unnecessary SIR system repairs
In order to avoid the above conditions, observe the following guidelines:
o Refer to SIR Component Views in order to determine if you are performing service on or near the SIR components or the SIR wiring.
o If you are performing service on or near the SIR components or the SIR wiring, disable the SIR system. Refer to Disabling the SIR System in SIR.
20. Disable the passenger side SIR system. Refer to Disabling the SIR System in SIR.
21. Remove the left and right instrument panel driver knee bolster brackets.
22. Lower the steering column for clearance. Refer to Steering Column Replacement in Steering Wheel and Column.
Important
Label all of the connections in order to avoid improper installation.
23. Remove the top instrument panel screws.
24. Roll the instrument panel down.
25. Disconnect the electrical connections, as needed.
26. Remove the fastener that retains the radio antenna cable to the instrument panel.
27. Remove the instrument panel from the vehicle. If replacing the instrument panel carrier, retain the parts for assembly of the new instrument panel carrier.
Heater/Vent Module Replacement
Removal Procedure
1. Remove the instrument panel. Refer to Instrument Panel (I/P) Carrier Replacement in Instrument Panel, Gages and Console.
2. Drain the engine coolant. Refer to Draining and Filling Cooling System in Engine Cooling.
3. On vehicles with automatic climate control only, cut the outer layer of the A/C evaporator and blower module in order to access the service access cover.
4. On vehicles with automatic climate control only, remove the service access cover mounting screws (1).
5. On vehicles with automatic climate control only, remove the service access cover (2).
6. On vehicles without automatic climate control, remove the blower motor resistor. Refer to Blower Motor Resistor Replacement .
Important
Mark and use the same mounting bolt for the heater/vent module during the installation process. Other mounting bolts are longer and will obstruct the operation of the temperature door.
7. Remove the heat/vent module mounting bolt through the blower motor resistor or service access cover opening.
8. On vehicles with A/C only, remove the right wheel house panel. Refer to Wheelhouse Panel Replacement in Body Front End.
9. On vehicles with A/C only, raise and support vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
10. On vehicles with A/C only, remove the front right tire. Refer to Tire and Wheel Removal and Installation in Tires and Wheels.
11. On the Utility only, remove the A/C evaporator and blower module heat shield screws.
12. On the Utility only, slide the A/C evaporator and blower module heat shield toward the front of the vehicle.
13. Remove the 2 lower heat/vent module mounting nuts.
14. On the Utility only, remove the A/C evaporator and blower module heat shield bracket.
15. Remove the bottom right heat/vent module mounting bolt from inside the vehicle.
Important
The heat/vent mounting stud has a flange on the inside and cannot be removed from under the hood. Stop turning the stud after the threads are off the heat/vent module.
16. On the Utility only, while an assistant inside the vehicle pulls the bottom right corner of the heat/vent module approximately 2.5 mm (1 in) back, remove the 2 heat/vent module mounting studs.
17. On vehicles with A/C only, lower the vehicle.
18. On vehicles with a 2.2 L engine only, remove the engine wiring harness bracket located at the rear of the intake manifold. Refer to Valve Rocker Arm Cover Replacement in Engine Mechanical - 2.2 L.
19. Remove the HVAC module mounting bolt located at the lower left side of the heater core to heater hose connection.
20. Remove the HVAC module mounting nut located at the lower right side of the heater core to heater connection.
Important
The heat/vent mounting stud has a flange on the inside and cannot be removed from under the hood. Stop turning the stud after the threads are off the heat/vent module.
21. On the Utility only, loosen the HVAC module mounting studs until the threads are free from the heat/vent module.
22. Disconnect all of the electrical connectors from the HVAC module.
23. Disconnect all of the vacuum lines from the heater assembly.
24. Disconnect the heater hoses from the heater core.
25. Remove the HVAC module from the vehicle.
Heater Core Replacement
Removal Procedure
1. Remove the heater/vent module. Refer to Heater/Vent Module Replacement .
2. Remove the heater core access cover screws.
3. Remove the heater core access cover.
4. Remove the heater core from the heater/vent module.
Installation Procedure
1. Install the heater core to the heater/vent module.
Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.
2. Install the heater core access cover. Tighten
Tighten the heater core access cover screws to 1.9 N·m (17 lb in).
3. Install the heater/vent module. Refer to Heater/Vent Module Replacement .
Have a Nice Day Mark
