NO.18 A/C DOES NOT WORK SUFFICIENTLY [WLT-1, WLT-2]

id010396913800

18

A/C does not work sufficiently.

DESCRIPTION

•  The A/C compressor magnetic clutch does not engage when the A/C switch is turned on.

POSSIBLE CAUSE

•  Improper refrigerant charging amount

•  Microswitch is stuck open

•  Open A/C magnetic clutch

•  Open circuit in related wiring harnesses

•  Poor ground of A/C magnetic clutch

•  A/C low/high pressure switch is stuck open.

•  A/C relay is stuck open.

•  Seized A/C compressor

•  Frost switch is stuck open

•  Open circuit in blower resistor

•  Poor blower switch ground

•  ECT sensor malfunction

•  Improper magnetic clutch clearance

Diagnostic procedure

STEP	INSPECTION		ACTION
1	• Turn the engine switch to the ON position (Engine off). • Set the fan switch to 1st, 2nd, 3rd, or 4th position. • Verify that the blower motor is operating. • Is the blower motor normal?	Yes	Go to the next step.
1		No	Inspect for the following: • Poor ground of fan switch • Open circuit in blower resistor • Poor contact of fan switch • Blower relay is stuck open • Open circuit in blower relay coil • Seized blower motor • Open circuit in blower motor coil • Open circuit between blower motor and resistor • Open circuit between fan switch and resistor Repair or replace if necessary.
2	• Turn the engine switch on. • Set the fan switch to 1st, 2nd, 3rd, or 4th position. • Measure the voltage at the PCM connector terminal G. Specification Less than 2.7 V • Is the voltage correct?	Yes	Go to the next step.
2		No	Inspect for the following: • Frost switch is stuck open • Poor contact of microswitch in heater control unit • Open circuit between PCM connector terminal G and frost switch connector terminal • Open circuit between frost switch connector terminal and fan switch connector terminal Repair or replace if necessary.
3	• Start the engine and run it at idle speed. • Set the fan switch to the 1st position. • Measure the voltage at the terminal from the A/C relay connector terminal E. Specification More than 10.5 V • Is the voltage correct?	Yes	Go to the next step.
3		No	Inspect for the following: • Open circuit A/C relay coil • Poor connect in A/C relay • A/C relay stuck open • Open circuit between PCM connector terminal N or L and A/C relay connector terminal • Open circuit in battery supply line • Open circuit between engine switch and A/C relay connector terminal • Engine coolant temperature sensor malfunction Repair or replace if necessary.
4	• Disconnect the A/C magnetic clutch connector. • Measure the A/C magnetic clutch connector terminal voltage. Specification More than 10.5 V • Is the voltage correct?	Yes	Inspect for the following: • Poor ground of the A/C magnetic clutch • Open circuit in the magnetic clutch coil • Refrigerant charging amount Repair or replace if necessary.
4		No	Inspect for the following: • Open circuit between the pressure switch connector terminal and A/C magnetic clutch connector terminal • Refrigerant changing amount • A/C pressure switch is stuck open. • Magnetic clutch clearance • A/C compressor is seized Repair or replace if necessary.
5	• Verify the test results. If normal, return to the diagnostic index to service any additional symptoms.

18	A/C does not work sufficiently.
DESCRIPTION	• The A/C compressor magnetic clutch does not engage when the A/C switch is turned on.
POSSIBLE CAUSE	• Improper refrigerant charging amount • Microswitch is stuck open • Open A/C magnetic clutch • Open circuit in related wiring harnesses • Poor ground of A/C magnetic clutch • A/C low/high pressure switch is stuck open. • A/C relay is stuck open. • Seized A/C compressor • Frost switch is stuck open • Open circuit in blower resistor • Poor blower switch ground • ECT sensor malfunction • Improper magnetic clutch clearance