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Carhelp4u
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98 Chevy blazer: replacing..it.I need some type of schematic to show

Resolved Question:

I have a 98 Chevy blazer and I am replacing the heatercore in it.I need some type of schematic to show how to dismantle the dash for the removal and replacement part
Submitted: 5 years ago.
Category: Chevy
Expert:  Carhelp4u replied 5 years ago.

Ok, Here is what you are going to need to do to gain access to the heater core.

  • On vehicles equipped with a manual transmission, remove the shift lever.
  • On vehicles equipped with an automatic transmission, perform the following steps:
    2.1. Apply the park brake.
    2.2. Insert the ignition key and turn the ignition switch to the RUN position.
    2.3. Depress the brake pedal and shift the transmission to the 1 position.
    2.4. Turn the ignition switch to the OFF position.

    Object Number: 392686  Size: SH

    Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

  • Disconnect the battery negative cable.
  • Remove the left sound insulator.
  • Remove the center sound insulator.
  • Remove the lower left instrument panel mounting bolt.
  • Remove and retain the instrument panel storage compartment.
  • Remove the lower right instrument panel mounting bolt.
    Object Number: 392691  Size: SH

  • Remove and retain the left and right speakers and the speaker grilles.
  • 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.
    Object Number: 392690  Size: SH

  • If equipped with a sun load temperature sensor, twist the sensor ¼ turn counterclockwise in order to disengage.
  • Disconnect the brown electrical connection from the body control module (BCM).
  • Disconnect the purple electrical connection from the body control module (BCM).
  • Remove the knee bolster.
  • Remove and retain the instrument cluster.
  • Remove and retain the radio.
  • Remove the HVAC control assembly.

    Caution: This vehicle is equipped with a Supplemental Inflatable Restraint (SIR) System. Failure to follow the correct procedure could cause the following conditions:

    Air bag deployment
    Personal injury
    Unnecessary SIR system repairs
    In order to avoid the above conditions, observe the following guidelines:
    Refer to SIR Component Views in order to determine if you are performing service on or near the SIR components or the SIR wiring.
    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.

     

  • Disable the passenger side SIR system.
  • Remove the key from the ignition switch.
  • Remove the SIR Fuse from the IP fuse block.

    Important: With the SIR Fuse removed and the ignition switch in the ON position, The AIR BAG warning lamp illuminates. This is normal operation, and does not indicate an SIR system malfunction.

  • Remove the sound insulator-LH.
  • Remove the knee bolster (if equipped).
    Object Number: 9041  Size: SH

  • Remove the Connector Position Assurance (CPA) from the driver yellow 2-way connector located at the base of the steering column.
    Object Number: 9042  Size: SH

  • Disconnect the driver yellow 2-way connector located at the base of the steering column.
  • Open the IP compartment door, lift stop and allow door to fully open.
    Object Number: 208427  Size: SH

  • Remove the Connector Position Assurance (CPA) from the passenger yellow 2-way connector located behind the glove box.
  • Disconnect the passenger yellow 2-way connector located behind the glove box.

  • Object Number: 392681  Size: SH

  • Remove the left and right instrument panel driver knee bolster brackets.
  • Lower the steering column for clearance.
    Object Number: 303370  Size: SH

    Important: Label all of the connections in order to avoid improper installation.

  • Remove the top instrument panel screws.
  • Roll the instrument panel down.
  • Disconnect the electrical connections, as needed.
  • Remove the fastener that retains the radio antenna cable to the instrument panel.
  • Remove the instrument panel from the vehicle.
    Object Number: 617612  Size: SH

  • Remove the instrument panel.
  • Drain the engine coolant.
  • 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.
    Object Number: 617623  Size: SH

  • On vehicles with automatic climate control only, remove the service access cover mounting screws (1).
  • On vehicles with automatic climate control only, remove the service access cover (2).
  • On vehicles without automatic climate control, remove the blower motor resistor.

    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.

  • Remove the heat/vent module mounting bolt through the blower motor resistor or service access cover opening.
    Object Number: 1595  Size: SH

    right wheel house panel.
  • On vehicles with A/C only, raise and support vehicle.
  • On vehicles with A/C only, remove the front right tire.
  • On the Utility only, remove the A/C evaporator and blower module heat shield screws.
  • On the Utility only, slide the A/C evaporator and blower module heat shield toward the front of the vehicle.
  • Remove the 2 lower heat/vent module mounting nuts.
  • On the Utility only, remove the A/C evaporator and blower module heat shield bracket.
  • 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.

  • 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.
  • On vehicles with A/C only, lower the vehicle.
    Object Number: 529580  Size: SH

  •  

  • Remove the HVAC module mounting bolt located at the lower left side of the heater core to heater hose connection.
  • 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.

  • On the Utility only, loosen the HVAC module mounting studs until the threads are free from the heat/vent module.
  • Disconnect all of the electrical connectors from the HVAC module.
  • Disconnect all of the vacuum lines from the heater assembly.
  • Disconnect the heater hoses from the heater core.
  • Remove the HVAC module from the vehicle.Object Number: 426946  Size: SH

  • Remove the heater core access cover screws.
  • Remove the heater core access cover.
    Object Number: 426950  Size: SH

  • Remove the heater core from the heater/vent module.
    Object Number: 426950  Size: SH

  • Install the heater core to the heater/vent module.
    Object Number: 426946  Size: SH

    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.

  • Install the heater core access cover.

    Tighten
    Tighten the heater core access cover screws to 1.9 N·m (17 lb in).

  • Install the heater/vent module.
    Object Number: 529580  Size: SH

  • If replacing the HVAC module, transfer the components from the old heat/vent module as necessary.

    Important: Before installing the HVAC module to the vehicle, ensure that the HVAC module mounting studs are located in the proper positions.

  • Install the HVAC module to the vehicle.
  • Connect the heater hoses to the heater core.
  • Connect all of the vacuum lines to the heater assembly.
  • Connect all of the electrical connectors to the HVAC module.
  • Install the bottom right HVAC module mounting bolt from inside the vehicle approximately halfway into the threads.

    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.

  • On the Utility only, install the HVAC module mounting stud located at the lower right side of the heater core to heater hoses connection in the engine compartment.

    Tighten
    Tighten the HVAC module mounting stud to 4.5 N·m (40 lb in).

  • On vehicles with A/C only, raise the vehicle.
  • On the Utility only, install the bottom right HVAC mounting studs. Ask an assistant to pull the bottom right corner of the HVAC module back from inside the vehicle.

    Tighten
    Tighten the heat/vent module mounting studs to 4.5 N·m (40 lb in).

  • On the Utility only, install the A/C evaporator and blower module heat shield bracket.
  • Install the heater/vent module mounting nuts.

     

    Tighten
    Tighten the HVAC module mounting nuts to 4.5 N·m (40 lb in).

  • On the Utility only, slide the A/C evaporator and blower module heat shield into the original position.
  • On the Utility only, install the A/C evaporator and blower module heat shield screws.

    Tighten
    Tighten the A/C evaporator and blower module heat shield screws 2.2 N·m (19 lb in).


    Object Number: 1595  Size: SH

  • On vehicles with A/C only, install the right front tire.
  • On vehicles with A/C only, lower the vehicle.
  • Install the bottom right HVAC module mounting bolt from inside the vehicle.

    Tighten
    Tighten the HVAC module mounting bolt to 4.5 N·m (40 lb in).

  • On vehicles with A/C only, install the right wheel house panel.
    Object Number: 529580  Size: SH

  • Install the HVAC module mounting nut located at the lower right side of the heater core to heater connection.

    Tighten
    Tighten the HVAC module mounting nut to 4.5 N·m (40 lb in).

  • Install the HVAC module mounting bolt located at the lower left side of the heater core to heater hose connection.

    Tighten
    Tighten the HVAC module mounting bolt to 4.5 N·m (40 lb in).

  • Important: Use the same mounting bolt marked during removal for the HVAC module during the installation process. Other mounting bolts are longer and will obstruct the operation of the temperature door.

  • Install the HVAC module mounting bolt through the blower motor resistor or service access cover opening.

    Tighten
    Tighten the HVAC module mounting bolt to 4.5 N·m (40 lb in).

  • On vehicles without automatic climate control, install the blower motor resistor.
    Object Number: 617623  Size: SH

  • On vehicles with automatic climate control only, install the service access cover (2).
  • On vehicles with automatic climate control only, install the service access cover mounting screws (1).

    Tighten
    Tighten the screws to 1.9 N·m (17 lb in).


    Object Number: 617612  Size: SH

  • On vehicles with automatic climate control only, install the outer layer of the A/C evaporator and blower module.

    Important: Do not use RTV. Apply the adhesive bead as straight as possible. Allow the adhesive to set for 15 minutes or until the adhesive becomes tacky.

  • Seal the cut line using black weather-strip adhesive.
  • Refill the engine coolant.
  • Install the instrument panel.
  • Enable the SIR System.
  • Feel free to contact me with any questions or problems! Good luck!
  • Carhelp4u, ASE CERTIFIED TECH
    Category: Chevy
    Satisfied Customers: 5203
    Experience: ASE CERTIFICATION
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