Symptom Chart - Climate Control Systems

WARNING: This page is about a different car, the 2009 Ford RV Cutaway, 2009 Ford Econoline, 2009 Ford E450 Super Duty, and 2009 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.

SYMPTOM CHART - CLIMATE CONTROL SYSTEMS

Condition	Possible Sources	Action
HVAC functions verification	HVAC system and/or related components	Go To PINPOINT TEST B .
Reduced outlet airflow	Circuitry short A/C compressor clutch air gap A/C cycling switch A/C clutch relay Blower motor Blower motor control Blower motor resistor Blower motor switch PCM	If the A/C compressor does not cycle, Go To PINPOINT TEST F . If the A/C compressor cycles normally, Go To PINPOINT TEST K .
Incorrect/erratic direction of airflow from outlets	Function selector switch Vacuum hose/harness Vacuum control motor A/C vacuum check valve Vacuum reservoir tank Air distribution door/linkage	Go To PINPOINT TEST C .
Insufficient, erratic or no heat	Low engine coolant level Engine overheating Plugged or partially plugged heater core Temperature blend door binding/stuck Temperature blend door actuator	Go To PINPOINT TEST D .
The air conditioning (A/C) is inoperative	Fuse(s) Circuitry open/short A/C cycling switch Low refrigerant system charge Function selector switch Pressure cutoff switch A/C control relay PCM A/C compressor clutch air gap A/C compressor clutch field coil	Go To PINPOINT TEST E .
The air conditioning (A/C) is always on - A/C compressor does not cycle	Circuitry short Function selector switch A/C control relay PCM A/C compressor clutch air gap	Go To PINPOINT TEST F .
The air conditioning (A/C) is always on - A/C mode always commanded ON	Circuitry short Function selector switch A/C control relay PCM A/C compressor clutch air gap	Go To PINPOINT TEST G .
Insufficient air conditioning (A/C) cooling - auxiliary system	Thermostatic Expansion Valve (TXV) Leaking or restricted vacuum hose Vacuum control motor Sticking mode door	Go To PINPOINT TEST H .
Temperature control is inoperative/does not operate correctly	Fuse(s) Circuitry open/short Temperature blend door actuator Temperature control switch	Go To PINPOINT TEST I .
The blower motor is inoperative	Fuse(s) Circuitry open/short Blower motor relay Function selector switch Blower motor	Go To PINPOINT TEST J .
The blower motor does not operate correctly	Blower motor switch Blower motor resistor Circuitry open/short	Go To PINPOINT TEST K .
The auxiliary blower motor is inoperative	Fuse(s) Circuitry open/short Auxiliary blower motor relay Auxiliary blower motor switch Auxiliary high speed blower motor relay Auxiliary blower motor	Go To PINPOINT TEST L .
The auxiliary blower motor does not operate correctly	Auxiliary blower motor switch Auxiliary blower motor resistor Circuitry open/short	Go To PINPOINT TEST M .
The auxiliary temperature/mode is inoperative/does not operate correctly	Auxiliary temperature actuator Auxiliary mode actuator Auxiliary vacuum source line	If both temperature and mode are affected, REPAIR the vacuum source line for an obstruction or leak. TEST the system for normal operation. If the temperature or mode alone are affected, INSPECT the temperature or mode door for a binding or broken condition. If no condition is found, INSTALL a new actuator. TEST the system for normal operation.
A/C pressure relief valve discharging	High system pressure A/C pressure relief valve	CHECK the high side system pressure. If the pressure is below the A/C pressure relief valve open pressure, INSTALL a new A/C pressure relief valve. If the system pressure is above the A/C pressure relief valve open pressure, REPAIR the system for a restriction