AC Evaporator

Complete removal and replacement of the AC evaporator, requiring full dashboard removal, AC system discharge and recharge, and refrigerant line disconnection.

Warnings

Tools required

Parts

• AC evaporator assembly × 1 — Use OEM specification
• Evaporator temperature sensor × 1 — Use OEM specification
• AC O-ring seal kit × 1 — Use OEM specification
• Expansion valve × 1 — Use OEM specification
• Receiver-drier × 1 — Replace whenever system is opened
• PAG oil for AC system × 1 — Use OEM-specified viscosity

Fluids

• R-134a

Preparation

1. Verify AC evaporator failure with diagnostic scan tool (check for temperature sensor codes, lack of cooling, persistent moisture in cabin).
2. Have vehicle AC system professionally discharged and refrigerant recovered by certified technician.
3. Disconnect battery negative terminal and wait minimum 15 minutes for airbag system discharge.
4. Remove both front seats to provide working space and prevent damage to upholstery.
5. Set steering wheel to straight-ahead position and lock steering column before disconnecting.
6. Document all fastener locations and connector orientations with photographs throughout the procedure.

Procedure

1. 1

   Remove Lower Dashboard Panels and Trim
   Remove lower dashboard trim panels on both driver and passenger sides. Locate and remove Torx fasteners securing lower trim sections (typically T20 or T25). Disconnect any electrical connectors for courtesy lights or diagnostic ports. Remove center lower trim panel beneath climate controls if present as a separate piece. Carefully release trim clips using plastic pry tools, working from edges inward.
2. 2

   Remove Center Console and Climate Control Interface
   Remove gear selector or Touchtronic control trim surround as applicable to this vehicle's transmission (pull upward after releasing clips). Remove console storage compartment liner to access hidden fasteners. Remove Torx fasteners securing center console sections. Disconnect electrical connectors for switches, power outlets, and climate control interface. Remove climate control head unit by removing surrounding trim bezel and fasteners, then disconnect harness connectors. Note and label all electrical connectors (the DB9 uses electrically actuated HVAC doors, not vacuum actuators). Note: Remove climate control head unit by removing surrounding trim bezel and E-Torx fasteners (typically E8), then disconnect harness connectors. Note: the DB9 climate system uses electric actuators rather than vacuum lines — verify actuator/electrical connections against OEM documentation before disconnecting. Note: Disconnect electrical connectors for switches, power outlets, and climate control interface. Remove climate control head unit by removing surrounding trim bezel and fasteners, then disconnect harness connectors. Label all connector routing.
3. 3

   Remove Steering Wheel and Column Shrouds
   With battery disconnected and 15 minutes elapsed, remove airbag module retaining fasteners from rear of steering wheel (typically T30 or T40 Torx). Carefully disconnect airbag harness connectors. Remove steering wheel center retaining fastener (verify nut vs bolt per OEM documentation) and withdraw the wheel from the splined shaft; use a steering wheel puller only if specified by the manufacturer. Remove upper and lower steering column shroud fasteners (Torx) and separate shrouds. Disconnect all steering column electrical connectors including stalks and ignition switch.
4. 4

   Remove Instrument Cluster and Side Trim Panels
   Remove instrument cluster bezel by releasing clips and removing fasteners. Disconnect instrument cluster electrical connectors and remove cluster assembly. Remove A-pillar trim panels on both sides by pulling firmly to release clips (start at top). Remove side dashboard end caps on both driver and passenger sides. These panels typically have hidden Torx fasteners accessible once lower panels are removed.
5. 5

   Disconnect Dashboard Electrical and Data Connectors
   Working methodically from left to right, disconnect all electrical harness connectors attached to dashboard components. This includes: HVAC blower motor, cabin temperature sensors, passenger airbag connector, glove box light, audio system harness, navigation/screen harness if equipped, and all switch modules. Release any harness retaining clips from dashboard structure. Label each connector with tape indicating its location.
6. 6

   Remove Main Dashboard Mounting Fasteners
   Locate main dashboard mounting points: typically found at each side end, center support brackets, and upper mounting points behind instrument cluster opening. Remove all E-Torx fasteners securing dashboard to cowl and firewall structure. Verify the exact dashboard mounting fastener type and size against the Aston Martin DB9 workshop manual before selecting tooling. Check for fasteners accessible through defroster vents at top of dashboard. Do not force dashboard if resistance is felt; verify all fasteners and clips are released.
7. 7

   Remove Dashboard Assembly
   With assistant support (dashboard is heavy and awkward), carefully pull dashboard rearward to disengage any remaining clips from cowl structure. Lift and angle dashboard to clear steering column opening. Maneuver dashboard out through passenger door opening. Set dashboard on protected surface in safe location. Verify no harnesses or lines remain connected before fully removing.
8. 8

   Access and Disconnect Evaporator Refrigerant Lines
   Locate evaporator housing behind firewall (now fully visible with dashboard removed). Identify refrigerant line connections at evaporator inlet and outlet (typically located on passenger side of firewall). Using appropriate wrench, disconnect refrigerant line fittings at evaporator. Immediately cap open lines and evaporator ports with refrigerant line plugs to prevent moisture and debris intrusion. Remove and discard old O-rings from line fittings.
9. 9

   Disconnect Evaporator Drain and Electrical Connections
   Disconnect evaporator temperature sensor electrical connector from evaporator assembly. Locate and disconnect evaporator condensate drain tube (rubber hose at bottom of evaporator case). Disconnect any additional electrical actuator connections to evaporator case or blend doors if present on this assembly.
10. 10

    Remove Evaporator Housing Assembly
    Remove fasteners securing evaporator housing to firewall and HVAC plenum. These are typically a combination of Torx screws and nuts accessible from cabin side. Carefully separate evaporator housing from blower housing/HVAC plenum, noting any sealing foam that may need replacement. Remove complete evaporator housing assembly into cabin.
    Torque spec

    Evaporator Case Screws5 Nm (4 lb-ft)
11. 11

    Disassemble Evaporator Housing and Remove Evaporator Core
    Place evaporator housing on clean work surface. Remove fasteners securing housing halves together (typically perimeter Torx screws). Carefully separate housing halves. Remove evaporator core from housing, noting orientation and any insulation foam placement. Remove expansion valve from old evaporator core. Inspect housing interior for debris, leaves, or biological growth; clean thoroughly if contamination present.
12. 12

    Install New Evaporator Core and Expansion Valve
    Install new expansion valve onto new evaporator core using new O-rings lubricated with PAG oil. Torque expansion valve to specification. Install evaporator temperature sensor into new evaporator (if sensor pocket is on core itself). Position new evaporator core into lower housing half with proper orientation. Ensure all insulation foam pieces are correctly positioned. Rejoin housing halves and install all perimeter fasteners, torquing case screws to specification.
    Torque spec

    Expansion Valve10 Nm (7 lb-ft)

    Evaporator Case Screws5 Nm (4 lb-ft)
13. 13

    Reinstall Evaporator Housing to Vehicle
    Position evaporator housing assembly to firewall and HVAC plenum. Install mounting fasteners and torque evaporator case screws to specification. Ensure proper sealing between evaporator housing and blower plenum (replace foam seals if damaged). Reconnect evaporator condensate drain tube. Reconnect evaporator temperature sensor connector.
    Torque spec

    Evaporator Case Screws5 Nm (4 lb-ft)
14. 14

    Reconnect Refrigerant Lines
    Install new O-rings onto refrigerant line fittings, coating with appropriate PAG oil. Remove protective caps from evaporator ports. Connect refrigerant lines to evaporator inlet and outlet ports. Torque AC line fittings to specification using backup wrench to prevent component damage. Verify fittings are fully seated before final torquing.
    Torque spec

    AC Line Fittings20 Nm (15 lb-ft)
15. 15

    Reinstall Dashboard Assembly
    With assistant support, carefully maneuver dashboard assembly through passenger door and position over steering column opening. Align dashboard to cowl and firewall mounting points. Install all main dashboard E-Torx mounting fasteners hand-tight first, then torque in sequence working from center outward. Reconnect all electrical harness connectors in reverse order of removal, verifying each connector is fully seated and locked.
16. 16

    Reinstall Remaining Interior Components
    Reinstall instrument cluster and connect harness. Install cluster bezel. Reinstall steering column shrouds. Reinstall steering wheel (align to straight-ahead position marked during removal), torque center nut to specification, reconnect airbag harness, and install airbag module with Torx fasteners. Reinstall climate control head unit and reconnect all electrical connectors. Reinstall center console sections and trim. Reinstall all dashboard trim panels, side end caps, A-pillar trim, and lower panels. Reinstall both front seats.
17. 17

    Evacuate and Recharge AC System
    Reconnect battery negative terminal. Have AC system professionally evacuated for minimum 30 minutes to remove all moisture. Verify system holds vacuum without loss (leak test). Recharge system with R-134a refrigerant to the exact capacity listed in the Aston Martin DB9 workshop manual (verify factory charge weight before charging; do not rely on estimates). Add appropriate amount of PAG oil to system if significant oil was lost during component removal. Use UV dye for future leak detection if desired.

Reassembly

1. During dashboard reinstallation, verify all harness connectors are reconnected before fully securing dashboard to prevent having to remove it again.
2. Check that all climate control vacuum lines are correctly routed and connected; incorrect routing will cause blend door operation failures.
3. Verify steering wheel is aligned to straight-ahead position before final tightening to prevent airbag light issues.
4. Ensure condensate drain tube is properly reconnected and routed to prevent water intrusion into cabin.

Verification

• Start engine and verify no airbag warning lights on instrument cluster. If airbag light is illuminated, check all airbag connector seating and clear codes with scan tool.
• Turn AC system to maximum cooling and verify cold air from all vents within 2-3 minutes of operation.
• Check evaporator temperature sensor reading with scan tool; should show temperature drop as system operates (typically 35-45°F when functioning correctly).
• Verify all climate control functions operate correctly including mode selection, temperature blend, and fan speeds.
• Inspect refrigerant line connections and evaporator case area for signs of refrigerant leaks using UV light if dye was added.
• Run AC system for 15-20 minutes and verify condensate drains properly from drain tube under vehicle (wet spot on ground beneath passenger side).
• Verify all interior trim panels are secure with no rattles or loose sections.
• Test all dashboard functions including gauges, lights, switches, audio system, and navigation to ensure no connector issues remain.

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