This procedure replaces the heater core in a 2012-2018 Jeep Wrangler 3.6L V6, requiring complete dashboard removal and coolant system drainage.

Warnings

Tools required

Parts

• Heater core × 1 — Mopar 68048903AA or equivalent
• Heater core tube O-rings × 2 — Use OEM specification
• HVAC housing foam seal tape × 1 — Use OEM specification
• Dashboard fastener assortment (replacement clips) × 1 — Use OEM specification

Fluids

• Mopar OAT Coolant (Purple) — 13 qt

Preparation

1. Ensure engine is completely cold to touch
2. Park vehicle on level surface and set parking brake
3. Disconnect negative battery terminal and wait 2 minutes minimum
4. Remove both front seats by removing four mounting bolts per seat for easier access
5. Place absorbent pads and towels under dash and on floor to catch coolant spills
6. Take photos of all wiring harness routing and connector positions around dashboard

Procedure

1. 1

   Drain cooling system
   Place drain pan under radiator. Remove radiator cap slowly to release any residual pressure. Open radiator drain petcock at bottom of radiator and drain coolant completely into pan. Remove coolant reservoir cap and drain reservoir with turkey baster or siphon into drain pan.
   Torque spec

   Drain Petcock8 Nm (6 lb-ft)
2. 2

   Disconnect heater hoses at firewall
   Locate heater core inlet and outlet hoses at firewall on passenger side of engine bay. Use hose clamp pliers to release spring clamps and slide back on hoses. Twist hoses gently to break seal, then pull off heater core tubes. Expect residual coolant spillage. Plug hoses with rags to minimize further drainage.
   ⚠Coolant will spill from hoses and heater core tubes. Have drain pan and towels ready.
   Torque spec

   Hose Clamps4 Nm (3 lb-ft)
3. 3

   Remove steering wheel and column covers
   Remove airbag module from steering wheel by accessing release clips on back of wheel. Disconnect airbag connector. Mark steering wheel position relative to shaft, then remove steering wheel retaining nut and use steering wheel puller to remove wheel. Remove upper and lower steering column covers by removing cover screws.
   ⚠️Handle airbag module carefully. Place face-up on clean surface away from work area.
   Torque spec

   Cover Screws12 Nm (9 lb-ft)
4. 4

   Remove instrument cluster and center console
   Remove instrument cluster bezel using trim tools to release clips. Remove four screws securing instrument cluster, pull cluster forward, and disconnect all electrical connectors. Label each connector. Remove center console by removing screws under cupholders and shift boot area, then lift console up and back to remove.
   Torque spec

   Cover Screws12 Nm (9 lb-ft)
5. 5

   Disconnect main dashboard wiring harnesses
   Working from both driver and passenger sides, locate and disconnect all main wiring harnesses from dashboard. This includes HVAC controls, radio connectors, climate control module, passenger airbag connector (if equipped), and all accessory connectors. Label each connection with wire labels or masking tape with position marked.
   ℹ️Take multiple photos before disconnecting each harness group for reassembly reference.
6. 6

   Remove dashboard mounting bolts
   Remove dashboard mounting bolts located at: four bolts along top edge near windshield (accessed after removing defroster grilles), two bolts at each A-pillar, two bolts at center near steering column support, and two bolts at passenger side footwell. Total of approximately 10-12 mounting bolts depending on trim level.
   Torque spec

   Mounting Bolts31 Nm (23 lb-ft)
7. 7

   Remove dashboard assembly
   With all bolts, wiring, and attachments disconnected, carefully pull dashboard rearward from windshield. Work from both sides to release dashboard from any remaining clips. Have assistant help support weight. Lift and tilt dashboard to remove from vehicle through passenger door opening. Set aside on padded surface to avoid damage.
   ⚠Dashboard is bulky and heavy. Use two people to avoid damage to dashboard or vehicle interior.
8. 8

   Remove HVAC housing cover
   With dashboard removed, access to HVAC housing is now clear. Remove screws securing HVAC housing upper cover. Carefully separate cover from housing, noting position of any foam seals or gaskets that must be reused or replaced.
   Torque spec

   Housing Bolts16 Nm (12 lb-ft)
9. 9

   Remove heater core
   Locate heater core inside HVAC housing. Remove heater core retaining bracket or screws. Carefully slide heater core out of housing, tilting as needed to clear housing walls. Expect residual coolant to drain from core—have towels ready. Inspect housing for debris or old seal material and clean thoroughly.
   ⚠Heater core fins are delicate. Avoid bending or damaging fins during removal.
10. 10

    Install new heater core
    Install new O-rings on heater core tubes with light coating of coolant for lubrication. Apply new foam seal tape to heater core mounting surfaces if original seals are damaged. Carefully slide new heater core into HVAC housing, ensuring tubes align properly with housing openings and core seats fully. Install retaining bracket or screws.
    ℹ️Ensure heater core is fully seated and tubes protrude through firewall properly before securing.
11. 11

    Reinstall HVAC housing cover
    Position HVAC housing cover, ensuring all foam seals are properly positioned. Install housing bolts and torque to specification. Verify all HVAC door mechanisms move freely and are not obstructed by heater core installation.
    Torque spec

    Housing Bolts16 Nm (12 lb-ft)
12. 12

    Reinstall dashboard assembly
    With assistant, carefully position dashboard assembly back into vehicle. Guide dashboard into position, aligning mounting points. Install all dashboard mounting bolts finger-tight first, then torque to specification working from center outward. Reconnect all electrical connectors using photos and labels as reference.
    Torque spec

    Mounting Bolts31 Nm (23 lb-ft)
13. 13

    Reinstall interior components
    Reinstall instrument cluster and connect all connectors. Install cluster bezel. Reinstall steering column covers with cover screws. Reinstall steering wheel aligning marks made during removal, torque nut to specification, reconnect airbag connector, and install airbag module. Reinstall center console. Reinstall front seats.
    Torque spec

    Cover Screws12 Nm (9 lb-ft)
14. 14

    Connect heater hoses and refill coolant
    In engine bay, install heater hoses onto heater core tubes at firewall. Ensure hoses are pushed fully onto tubes, then install hose clamps. Close radiator drain petcock and torque to specification. Fill cooling system with Mopar OAT Purple coolant through radiator opening until full. Fill coolant reservoir to MAX cold line.
    Torque spec

    Drain Petcock8 Nm (6 lb-ft)

    Hose Clamps4 Nm (3 lb-ft)
15. 15

    Bleed cooling system and test
    Reconnect battery negative terminal. Start engine and allow to warm to operating temperature with heater on maximum heat and fan on high. Monitor coolant level and add as needed. Check for leaks at heater hose connections at firewall. Squeeze upper radiator hose several times to help purge air. When cooling fan cycles on, shut off engine and recheck coolant level when cool. Top off as needed to MAX line.
    ⚠Monitor temperature gauge during bleeding process. Do not allow engine to overheat.

Reassembly

1. Verify all dashboard mounting bolts are torqued to specification
2. Confirm all electrical connectors are fully seated and locked
3. Test all dashboard functions including HVAC controls, gauges, lights, and accessories
4. Verify heater produces hot air at all blower speeds and temperature settings
5. Check passenger airbag warning light functions properly if equipped

Verification

• Start engine and verify no coolant leaks at heater core hose connections at firewall
• Confirm heater produces hot air within 5 minutes of engine reaching operating temperature
• Verify coolant level remains stable in reservoir after test drive
• Check under passenger carpet and floor mat for any signs of coolant leakage
• Test all HVAC modes (defrost, floor, vent) and verify proper airflow from all vents
• Confirm no coolant smell inside vehicle cabin
• Verify temperature gauge reads normal operating temperature and cooling fan cycles properly

More procedures for this vehicle