A/C Always On/A/C Compressor Runs Continuously - Mazda B-Series 1997 Workshop Manual

FT
TROUBLESHOOTlNG GUIDE
A/C ALWAYS ON
AIC COMPRESSOR RUNS CONTINUOUSLY
DESCRIPTION
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N C compressor magnetic clutch does not disengage
_1
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STEP
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INSPECTION
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ACTION
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N C and defroster OFF. Disconnect AIC clutch
connector. Connect a DVOM between the power pin
Connect N C clutch
1
and ground pin at the AIC clutch vehicle harness Refer to the 1997 8-series BETM to check the heater
! connector. Start engine. Monitor voltage.
1
Is voltage less than 2.0 volts?
2
'
3
- -
4
5
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breakout box less than 1.0 volt?
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Yes
No
Yes
No
Yes
No
Key OFF. Connect New Generation Star (NGS)
tester to data link connector. Start engine. N C and
defroster off. Access and view N C cycling switch
(ACCS) PID.
Is ACCS PID off?
Key OFF. Disconnect N C cycling switch.
Key ON, engine off. Access the ACCS PID.
Is the ACCS PID off?
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- -
Key OFF. Disconnect wide open throttle N C cutout
relay. Key ON.
Is voltage between power-to-clutch of WAC relay
vehicle harness connector and chassis ground less
than 1.0 volt?
box, leave PCM disconnected.~e~ ON.
6 Key OFF. Connect wide open throttle N C cutout
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Yes Replace PCM
relay. N C cycling switch disconnected. Breakout
box installed. PCM disconnected. Kev ON.
Refer to the 1997 B-series BETM to check the heater
and air conditioning systems
Go to next step
KeyOFF
Refer to the 1997 B-series BETM to verify the
operation of the N C switch
If OK, repair short to power in N C switch to N C
cycling switch circuit
Key OFF
Go to next step
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Key OFF
Go to next step
Key OFF
Repair short circuit to power
Key OFF. Disconnect N C cycling switch and wide
open throttle N C cutout relay. Disconnect PCM and
inspect for damage, moisture, pushed out pins,
loose wires. Service as necessaw. Install breakout
Is voltage between ACCS test pin 41sand PWR
GND test pin 51 and PWR GND test pin 103 at
No Replace wide open throttle N C cutout relay
breakout box less than 1.0 volt?
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Is voltage between ACCS test pin 41 and PWR
GND test in 51 and PWR GND test oin 103 at
No
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7 Verify test results. If OK, return to diagnostic index to service any additional symptoms
MF4082-B 6BUOFT-034
Yes
Repair short to power in ACCS circuit
Go to next step