Ford Mustang (1999-2004) Service Manual: Symptom Chart

Condition Possible Sources Action
  • Incorrect/erratic direction of airflow from outlet(s)
  • No vacuum to A/C heater function switch selector.
  • A/C heater function selector switch leaks vacuum.
  • Kinked/pinched vacuum hose.
  • Leaking vacuum control motor.
  • Leaking A/C vacuum check valve.
  • Leaking A/C vacuum reservoir tank and bracket.
  • Vacuum actuator arm not connected to door crank.
  • Go To Pinpoint Test A .
  • Insufficient, erratic, or no heat
  • Low engine coolant level.
  • Thermostat stuck open.
  • Disengaged/damaged temperature cable.
  • Go To Pinpoint Test B .
  • Insufficient, erratic, or no heat
  • CASS strategy failure.
  • Open fuses.
  • A/C clutch relay.
  • Shorted blend door actuator.
  • Powertrain control module.
  • Circuitry short/open.
  • A/C cycling switch damaged.
  • A/C system discharged/low charge.
  • Function selector switch damaged.
  • A/C pressure cut-off switch damaged.
  • A/C compressor clutch damaged.
  • Go To Pinpoint Test C .
  • The A/C is always on
  • Circuitry short/open.
  • A/C cycling switch.
  • A/C heater function selector switch.
  • Constant control relay module.
  • Incorrect A/C clutch air gap.
  • Go To Pinpoint Test D .
  • Insufficient A/C cooling
  • Restricted A/C evaporator core orifice.
  • Low refrigerant level.
  • Go To Pinpoint Test E .
  • No operation in all the temperature settings
  • Damaged blend door actuator cable.
  • Damaged air temperature control door.
  • Go To Pinpoint Test F
  • The blower motor does not operate
  • Open fuse.
  • Circuitry open/shorted.
  • Damaged heater blower motor switch (18578).
  • Damaged heater blower motor switch resistor (18591).
  • Damaged blower motor relay.
  • Damaged blower motor
  • Go To Pinpoint Test G .
  • The blower motor operates continuously in high speed
  • Circuitry short/open.
  • Damaged heater blower motor switch resistor.
  • Damaged heater blower motor switch.
  • Go To Pinpoint Test H .
  • No operation in high blower setting
  • Circuitry short/open.
  • Damaged heater blower motor switch.
  • Go To Pinpoint Test I .
  • No operation in lower speeds
  • Circuitry short/open.
  • Damaged heater blower motor switch resistor.
  • Damaged heater blower motor switch.
  • Go To Pinpoint Test J .
    Inspection and Verification
    1. Verify the customer's concern by operating the climate control system to duplicate the condition. 2. Inspect to determine if one of the following mechanical or electrical concerns apply: Visu ...

    Pinpoint Tests
    PINPOINT TEST P1464: DTC P1464: A/C DEMAND OUT OF SELFTEST RANGE Test Step Result / Action to Take P14641 RECHECK FOR THE DTC YesGO to P14642 . No The system is functioning correc ...

    Other materials:

    Air filter check
    WARNING: To reduce the risk of vehicle damage and or personal burn injuries, do not start your engine with the air cleaner removed and do not remove it while the engine is running. Note: Failure to use the correct air filter element may result in severe engin ...

    Removal
    1. Disconnect the battery negative cable. 2. Drain the engine cooling system. 3. Remove the RH exhaust manifold. For additional information, refer to Exhaust Manifold RH in this section. 4. Remove the lower intake manifold. For additional information, re ...

    Universal Garage Door Opener (If Equipped)
    UNIVERSAL GARAGE DOOR OPENER The appearance of your vehicle’s universal garage door opener will vary according to your option package. Before programing, make sure you identify which transmitter you have by comparing it to the graphics below. HomeLink® Ca ...