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:

    Manual Transmission and Clutch (Description and Operation)
    The primary function of the clutch is to couple and uncouple engine power to the transmission upon driver command. For additional information, refer to Section. Clutch Disc and Clutch Pressure Plate - 3.8L   Clutch Disc and Clutch Pressure Pl ...

    Sun visors
    Slide-On-Rod Rotate the visor toward the side window and extend it rearward for extra sunlight coverage. Retract the visor before moving it back toward the windshield and storing it. Illuminated Visor Vanity Mirror Lift the cover to switch on the lamp. Flex ...

    Principles of Operation
    Multifunction Wipers The front wiper/washer feature controls the speed of the front windshield wipers and the amount of washer fluid sprayed on the front windshield when requested by the customer. There are five (5) wiper modes: OFF, LOW, HIGH, INT ...