Pontiac Fiero 1988 Service Manual page 1060

AIR CONDITIONING:
COMPRESSOR CONTROLS
C60, MANUAL
(Continued from previous page)
• If both voltages are correct, but clutch
does not engage when connected, replace
the A / C Compressor Clutch.
1. Check for open in D K GRN (59)
wire.
2. Check for open in B L K (153)
wire to
ground.
C: A/C COMPRESSOR FUNCTION
CONTROL TEST
Measure: VOLTAGE
At: A / C CONTROL HEAD CONNECTOR
(Connected)
Conditions:
• Ignition
Switch: RUN (Engine need not
be running)
• A / C Mode: NORM
• Temperature Outside Car: ABOVE 60°F
(16°C)
Measure
Between
N (BRN) &
Ground
G (LT GRN) &
Ground
Correct
Voltage
Battery
Battery
For Diagnosis
Seel
See
2
• If both voltages are correct, go to CI.
1. Check for open HTR A/C Fuse or open
B R N (50)
wire.
2. Replace A/C Control Head.
CI. Measure the voltage at terminal A of the
A/C Compressor Control Relay with a fused
jumper connected across the terminals of
the A/C Low Pressure Switch connector
(disconnected).
• If battery voltage is present, refer to
Section IB to check for normal re-
frigerant charge. If refrigerant charge is
normal, replace the A/C Low Pressure
Switch.
• If battery voltage is not present, go to
C2.
02. Measure the voltage at terminal A of the
A/C Compressor Control Relay with a fused
jumper connected across the terminals of
the A/C High Pressure Cut-Out Switch
connector (disconnected).
• If battery voltage is present, replace the
A/C High Pressure Cut-Out Switch.
• If battery voltage is not present, check
the wiring between the switches back to
the A/C Control Head (see schematic).
SYSTEM DIAGNOSIS
V6 VIN 9
• Use the Isolation Tests below to choose the
proper diagnostic tests.
ISOLATION TEST (TABLE 1)
Measure: VOLTAGE
At: A/C COMPRESSOR CONTROL RELAY
CONNECTOR (Disconnected)
Conditions:
• Ignition Switch: RUN (Engine need not
be running)
• A / C Mode: NORM
• Temperature Outside Car: ABOVE 60°F
d i ° C )
(Continued in next column)
(Continued from previous column)
Measure
Between
Correct
Voltage
For Diagnosis
D
(BLK/WHT)
& Ground
Battery
Check
BLK/WHT
(922) wire for
an open
A (LT BLU)
& Ground
Battery
Check LT
B L U (67) wire
for an open
If wire is good,
do Test C
• If voltages are correct, leave the A/C Com-
pressor Control Relay disconnected and go
to Table 2.
ISOLATION TEST (TABLE 2)
Conned:
msm mmpm
At:
A/C
COMPRESSOR
CONTROL RELAY
CONNECTOR (Disconnected)
Conditions:
• Ignition Switch: RUN (Engine not
running)
• A/C Mode: NORM
• Temperature Outside Car: ABOVE 60°F
(16°C)
Jumper
Between
Correct Result For Diagnosis
D (BLK/
W H T ) & B
(DK GRN)
Clutch
engages
Do Test B
• If the result is correct, do Test A.
(Continued on next page)