Workshop Manuals Factory service & repair Aston Martin
Aston Martin DB9 Factory Workshop Manual (Issue 2, 2005)13 · 12 Climate control
13 · Heating & A/C

Removal (page 3 of 5)

Make
Aston Martin
Model
DB9 Factory Workshop Manual
Year
Issue 2, 2005
Section
Air Conditioning (A/C) System
12 Climate controlRemoval · page 3 of 5

The areas for inspection (steps) are given according to various circuit malfunctions. Use the following chart to verify the symptoms of the trouble in order to diagnose the appropriate area.

Symptom(1)DescriptionPossible Cause
Insufficient air (or no air) blown from vents. Problem with each vent / duct or both.
Airflow mode does not change.
  • Fault in Airflow Mode Actuator
  • Fault in ‘Vent’ mode system
  • Fault in ‘Heat’ mode system
  • Fault in ‘Defroster’ mode system
Symptom(2) Description Possible Cause
Amount of air blown from vents does not change. Fault in blower system.
  • Blower motor fault
  • Blower unit fault
  • Power transistor system fault
  • Climate control unit fault
Shake the wiring harness and connectors while performing the inspection to discover whether poor contact points are the cause of any intermittent malfunctions. If there is a problem, check to make sure connectors, terminals and wiring harnesses are connected correctly and undamaged.
Symptom(3) Description Possible Cause
Air intake mode does not change. Air intake mode does not change when switching REC FRESH mode.
  • Air Intake Actuator fault
  • Air intake door fault
Shake the wiring harness and connectors while performing the inspection to discover whether poor contact points are the cause of any intermittent malfunctions. If there is a problem, check to make sure connectors, terminals and wiring harnesses are connected correctly and undamaged.
Symptom(4) Description Possible Cause
No temperature control with A/C Module. Temperature does not change with operating temperature control dial
  • Air Mix Actuator (5 V signal) system fault
  • A/C Module (potentiometer GND signal) system fault
  • Air Mix Actuator (potentiometer input signal) system fault
  • Air Mix Actuator (potentiometer GND signal, motor drive signal) system fault
  • Air Mix Actuator system fault
  • A/C unit air mix door fault
Shake the wiring harness and connectors while performing the inspection to discover whether poor contact points are the cause of any intermittent malfunctions. If there is a problem, check to make sure connectors, terminals and wiring harnesses are connected correctly and undamaged.
Symptom(5) Description Possible Cause
Windshield fogged.
  • A/C compressor does not operate while airflow mode is in DEFROSTER or HEAT DEF modes
  • Air intake mode does not change to FRESH while airflow mode is in DEFROSTER or HEAT DEF modes
  • A/C Module (B+ signal) system fault
  • Air intake actuator fault
  • A/C Module (RECIRCULATE, FRESH signal) system fault
  • Fault in blower unit air intake doors
Shake the wiring harness and connectors while performing the inspection to discover whether poor contact points are the cause of any intermittent malfunctions. If there is a problem, check to make sure connectors, terminals and wiring harnesses are connected correctly and undamaged.

Parts & tools for this job For 2005 Aston Martin DB9

Links open Amazon search results in a new tab. As an Amazon Associate I earn from qualifying purchases.