Diagnostic procedure

WARNING: This page is about a different car, the 2005 Mazda RX-8. However, it is still accessible from the selected car via links, so may be relevant.

NO.23 A/C DOES NOT WORK SUFFICIENTLY DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	Connect the WDS or equivalent to the DLC-2. Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	DTC is displayed: Go to the applicable DTC inspection. (See DTC TABLE .)
1		No	No DTC is displayed: Go to the next step.
2	Disconnect the A/C compressor connector. Start the engine and turn the A/C switch on. Is there correct voltage at the terminal of the A/C compressor magnetic clutch connector? Specification 10.5 V or more	Yes	Inspect for GND condition of magnetic clutch on the A/C compressor. If the GND condition is normal, inspect for an open circuit in the magnetic clutch coil.
2		No	Go to the next step.
3	Disconnect the refrigerant pressure switch connector. Connect the jumper wire between the terminals of the A/C high pressure switch connector. Connect the jumper wires between the terminals of the refrigerant pressure switch connector. Turn the ignition switch to the ON position. Turn the A/C switch on and set the blower fan to any speed. Does the A/C work?	Yes	Inspect the refrigerant pressure switch operation. If the switch is normal, go to the next step.
3		No	Inspect for the following: The A/C switch is stuck open. Open circuit between refrigerant pressure switch and PCM terminal 4W Open circuit between blower motor fan switch and resistor (if blower motor does not operate) Evaporator temperature sensor and A/C amplifier
4	Remove the jumper wire from the switch connector. Reconnect the connector to the refrigerant pressure switch. Start the engine and turn the A/C switch on. Does the fan operate?	Yes	Inspect whether the A/C relay is stuck open. Replace if necessary.
4		No	Inspect the following and repair or replace if necessary: Refrigerant charging amount A/C compressor for seizure
5	Verify test results. If normal, return to the diagnostic index to service any additional symptoms. If the malfunction remains, inspect the related Service Bulletins and/or the On-line Repair Information and perform the repair or diagnosis.