Heater Core Replacement Procedures

2002 Jeep Grand Cherokee
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JC Whitney - Truck, SUV, and Van

How to Replace the Heater Core on a 2002 Jeep Grand Cherokee

By Melissa Kelly, eHow Contributor

How to Replace the Heater Core on a 2002 Jeep Grand Cherokeethumbnail     
Replacement of a heater core can take up to eight hours.

If the windshield on your Jeep Grand Cherokee won't properly defrost or the passenger side of the vehicle has a wet floor board, the heater core may be at fault. Heater core removal can be a difficult task for a home mechanic, however, if done in a slow and methodical manner with attention to detail, particularly wiring and fasteners, it can be a successful endeavor. Make sure you allocate enough time for the project in order to avoid rushing, particularly since the entire instrument panel must be removed to access the heater and air conditioning unit. (See below for the procedures for removing dashboard.)

Difficulty: Moderately Challenging

Instructions

Things You'll Need

  • Coolant drain reservoir
  • Straight-slot screwdriver
  • Open-end wrench
  • Socket
  • Pliers
  • Heater core with new O-rings
  • Rubber cement
  • Coolant

 

  1. Heater Core Removal

    • 1. Discharge the air conditioning system pressure by taking your Jeep to a dealership or service center. The system's fittings are under high pressure, so do not attempt to disconnect the fittings prior to evacuation of the freon.
    • 2. Disconnect the negative cable from the battery's terminal. Drain the cooling system into a disposal container from the radiator and the engine block drain plugs. Disconnect the heater hoses at the inlet and the outlet of the heater core.
    • 3. Remove the console, lower the steering column and remove the instrument panel assembly. To remove the console, position the shift lever in the fully rearward position and remove the front and rear storage bins. Then remove the console mounting screws, lift the console upward, disconnect electrical connectors and remove the console. Use the lever on the side of the steering wheel to lower the steering column to its lowest position. To remove the instrument panel assembly, use a trim tool to pry the attachment clips loose to release both the upper and lower panels. Remove the ashtray and disconnect electrical connectors behind each panel.
    • 4. Disconnect the blower motor electrical connector, which is located under the glove compartment area of the dash near the firewall. Bend back the clip on one of the mounting screws and release the wiring harness. Pull the harness down and disconnect the electrical connector.
    • 5. Disconnect the air-conditioning lines from the evaporator by unbolting the refrigerant lines from the firewall with a wrench.
    • 6. Remove the coolant reservoir by loosening the hose clamp and detaching the hose from the reservoir. Disconnect the electrical connector from the coolant level sensor. Remove the screws and lift the reservoir out of the vehicle.
    • 7. Detach the PCM computer from the firewall, but do not disconnect the 60-pin connector. Pull the PCM far enough away to remove the heater/air conditioning unit attaching nuts from the studs on the engine compartment side of the firewall. There are three nuts behind the computer and one at the center of the firewall.
    • 8. Label the electrical connectors of the heater/air conditioning unit and the blower motor resistor/control module. Disconnect the electrical connectors. Disconnect the vacuum hose at the vacuum motor. Remove the evaporator drain tube. Remove the defrost duct, locate above the heater/air conditioning unit.
    • 9. Disconnect the rear floor heating duct from the center adaptor heat duct.
    • 10. Remove the nuts from the studs on the interior side of the firewall and pull the heater/air conditioning unit from the vehicle.
    • 11. Remove the retaining screws and remove the heater core from the top of the unit by pulling it straight up and out of the housing.

    Installation

    • 1. Position the new heater core into the housing and reinstall the retaining screws. Install the heater core and cement the seal in place to keep it from moving during installation of the blower assembly.
    • 2. Reinstall the remaining components in reverse order of removal. When reinstalling the coolant tubes to the heater core, install the new O-rings before clamping the tubes to the core. When installing the blower/evaporator housing, avoid pinching the wiring between the housing's air inlet and the instrument panel on the right side of the housing.
    • 3. Refill the air conditioning coolant system by adding coolant to the radiator and reservoir until full. Start the engine to check for proper operation of the heating system. Do not turn on the air conditioning system until it has been recharged and leak-tested.



Read more: How to Replace the Heater Core on a 2002 Jeep Grand Cherokee | eHow.com http://www.ehow.com/how_6714641_replace-2002-jeep-grand-cherokee.html#ixzz1ZS4MxHfT

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NOTE:  If you are seeing coolant leak problems from the heating system, you most likely have a failed heater core. If the problem is lack of heat and/or AC control, the problem is more likely to be the blend door. Blend door failure is a very common problem on the Jeep Grand Cherokee.

Read more: http://wiki.answers.com/Q/How_do_you_change_heater_core_in_a_2002_Jeep_Grand_Cherokee_with_a_v-8#ixzz1ZSEya0nb

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2002 Jeep Grand Cherokee Dashboard Removal

By Mindi Orth, eHow Contributor 

updated January 31, 2011

Related Searches:

2002 Jeep Grand Cherokee Dashboard Removalthumbnail

Remove the dashboard to repair the air conditioning evaporator, heater core and other components.

Replacing certain components in a 2002 Jeep Grand Cherokee, such as the heater core or air conditioner evaporator, requires the complete removal of the dashboard. At least a two person job, the time consuming process of removing the Grand Cherokee's dashboard can be both difficult to accomplish and dangerous. Only professional mechanics or individuals truly experienced in home vehicle repair should attempt to remove the dashboard of the Jeep Grand Cherokee.

Difficulty:  Challenging

Instructions

Things You'll Need

  • Metric socket set
  • Metric wrench set
  • Phillips screwdriver
  • Assistant

 

    • 1. Use a wrench to disconnect the negative cable from the battery terminal.
    • 2. Remove the screws located at the bottom of the instrument panel and steering wheel column holding the knee blocker in place. Find the screws on each side of the steering column, the outer edge of the knee blocker, and where the knee blocker attaches to the support frame. Place all screws off to the side.
    • 3. Pry the knee blocker away from the panel retaining clips.
    • 4. Remove the lower instrument panel armature by removing the bolts securing it to the support and then place the bolts off to the side.
    • 5. Remove the upper and lower steering column shrouds by prying them apart and then use a screwdriver to disconnect all wiring connectors from the steering column switches.
    • 6. Remove the nuts securing the steering column toe plate to the dash panel and place them to the side.
    • 7. Remove the nuts holding the steering column mounting bracket to the steering column and brake pedal support. Gently set the steering column down to the floor.
    • 8. Disconnect the wiring connector located under the left side of the instrument panel and unplug the brake lamp switch connector.
    • 9. Remove the heater controls wire harness connector located under the passenger side of the instrument panel, and then disconnect the radio antenna cable located near the right side of the cowl panel.
    • 10. Disconnect all instrument panel connectors located on the right side of the cowl panel from the junction block.

    • 11. Move the floor carpeting away from the transmission hump.
    • 12. Remove the bolts securing the center bracket of the instrument panel to the driver's side floor and place them to the side. You then need to remove the bolt connecting the instrument panel to the steering column and brake pedal supports, and the bolts securing the instrument panel to the side panels of the cowl. Place all bolts off to the side.
    • 13. Remove the bolts securing the each end of the instrument panel to the windshield fence, and then remove the nuts holding the top of the instrument panel to the windshield fence. Place all nuts and bolts off to the side.
    • 14. Lift the instrument panel and dash off the windshield fence studs and remove the panel out through the passenger side front door. This will require the assistance of another person. Use care to avoid tearing the seats.
    • 15. Reverse the steps to reassemble the dashboard and instrument panel.



Read more: 2002 Jeep Grand Cherokee Dashboard Removal | eHow.com http://www.ehow.com/how_7579704_2002-grand-cherokee-dashboard-removal.html#ixzz1ZSHEA000