1988 PONTIAC FIERO ignition

AIR CONDITIONING: COMPRESSOR CONTROLS
C60, MANUAL
(Continued from previous page)
A: ECM COMPRESSOR CONTROL
TEST (TABLE
3)
Connect: FUSED JUMPER
At: ECM CONNECTOR (Disconnected)
Conditions:
0 Ignition Switch: RUN
(Engine need not be running]
AIC Mode: NORM
Temperature Outside Car: Above 60 OF
(16°C)
Jumper
Correct Action For Diagnosis
Between
engages
r If action is correct but A/C system does
not operate under normal conditions, con-
dition
is due to ECM. Refer to Section 6E
for ECM diagnostics.
1. Replace AIC Compressor Control Relay.
Corm
ILT BLU'
and Ground
B: AIC COMPRESSOR CLUTCH TEST
Measure: VOLTAGE
At:
AIC COMPRESSOR CLUTCH
(Disconnected)
Conditions: Ignition Switch: RUN
(Engine need not
be running)
r Ale Mode: NORM
Temperature Outside Car: Above
60 OF
116OC)
Compressor
Control Relay
operates
&
AIC Clutch (Continued from previous column)
1
See 1
Measure
I Between Correct I For
Diagnosis I I Vdtaas
/ (DK GRN' I Battery I See 1 & Ground
I BLz,",":' ( Battery I See 2
If voltages are correct hut clutch does not
engage, replace the Compressor Clutch.
I 1. Check for open in DK GRN (959) wire. 1
2. Check for open in BLK (150) wire.
C: AIC COMPRESSOR FUNCTION
CONTROL TEST
lgnition Switch: RUN
(Engine need not be running)
A/C Mode: NORM
open NTR-AIC Fuse or open
61. Remove the connectors from the Pressure
Cycling Switch and the
A/C High Pres-
sure Switch. Connect a fused jumper
between the ter
als of the connectors.
If switch is open, battery voltage will be
present at terminal
E of the AlC Com-
pressor Control Relay, when the jumper is
connected.
0 If the Pressure Cycling Switch is open, refer
to Section
1B to check for normal refrigerant
charge. If refrigerant charge is low, follow
procedures in Section
1B for refrigerant
diagnostics.
If refrigerant charge is normal,
replace the Pressure Cycling Switch.
@ If A/C High Pressure Cut-Out Switch is
open, replace it.
0 If both switches are good but battery volt-
age is not present at the
AIC Compressor
Control Relay, check the wiring between
switches for
an open (see schematic).
SYSTEM DIAGNOSIS
V8 VlN F, V8 VIN 8
@ Use the Isolation Test below to choose the
proper diagnostic tests.
Tests follow the Isolation Test.
(Continued in next co

AIR CONDITIONING: COMPRESSOR
660, MANUAL
ISOLATION TEST (TABLE 1)
Measure: VOLTAGE
At: PRESSURE CYCLING
SWITCH
CONNECTOR (Disconnected)
Conditions: lgnition Switch: RUN
(Engine need not be running)
0 AIC Mode: NORM
Temperantre Outside Car: Above 60" F
(16" C)
Measure
Between Correct For Diagnosis /
I ILT Ground GRN'8rl Battery I Do Test B I
. If voltage is correct, leave Pressure
Cycling Switch disconnected and go to
Table
2.
ISOLATION TEST (TABLE 2)
Connect: JUMPER
At: PRESSURE CYCLING SWITCH
CONNECTOR (Disconnected)
Conditions: lgnition Switch: RUN
(Engine need not be running)
@ AIC Mode: NORM
0 Temperature Outside Car: Above 60" F
(16" C) I
Jumper I Correct Ac~on 1 For Diagnosis I I Between
If action is correct, refer to Section 1B for I
B (LT GRN) &
A (LT BLU)
I procedure to check refrigerant pressure. I
If refrigerant pressure is normal, replace
the Pressure Cycling Switch.
Clutch
engages
CONTROLS
Do Test A
A: Pale COMPRESSOR CLUTCH TEST
Measure: VOLTAGE
At:
A/C COMPRESSOR CLUTCH
(Disconnected)
Conditions:
0 Ignition Switch: RUN (Engine need not
be running)
0 AIC Mode: NORM
Temperature Outside Car: Above 60
OF
(16°C)
. Pressure Cycling Switch:
RECONNECTED
I
I ':"A':,",":' 1 ~attery I See 2 I
If voltages are correct but clutch does not
engage, replace the Compressor Clutch.
1. Check that AIC High Pressure Cut-Out
Switch is closed (see schematic). If
it is
open, replace it. Check for
an open in the
LT BLU
(67) and DK GRN (59) wires.
2. Check for an open in the BLK (150) wire.
Check that ground 6112 is clean and
tight.
B: AIC COMPRESSOR FUNCTION
CONTROL TEST
Measure: VOLTAGE
At: AIC CONTROL HEAD
Conditions: lgnition Switch: RUN
A/C Mode: NORM
0 Temperature Outside Car: Above 60" F
(16" C)
(Continued in next colum)
(Continued from previous column)
Measure Correct For Diagnosis
Between Voltage
Battery 1 See 1
Replace Ale
Control Head
If voltages are correct, check for an open
in the LT GRN
(66) wire.
1. Check for open HTR-AIC Fuse or open
BRN (50) wire.
SYSTEM DlAGlUOSlS
V8 VlN H
0 Use the isolation Test below to choose the
proper diagnostic tests.
Tests follow the Isolation Test.
lSOLATlOlU TEST (TABLE 1)
At: PRESSURE CYCLING SWITCH
CONNECTOR (Disconnected)
Ignition Switch: RUN
(Engine need not be running)
. A/C Mode: NORM
ramre Outside Car: Above 60 OF
Measure
I Between Correct I For Diagnosis I
Battery I Do Test B I I I
. If voltage is correct, leave Pressure
1 Cycling switch disconnected and go to I
(Continued on next page)

AIR CONDITIONING: COMPRESSOR CONTROLS
C60, MANUAL
(Continued from previous page)
lSOLATlON TEST (TABLE 2)
Connect: JUMPER
At: PRESSURE CYCLING SWITCH
CONNECTOR (Disconnected)
Conditions:
lgnition Switch: RUN
(Engine need not be running)
0 AIC Mode: NORM
r Temperamre Outside Car: Above 60°F
Jumper I Correct Action I For Diagnosis I Between
B (LT GRN) & Clutch
A (LT BLU) engages Do
Test A
0 If action is correct but AIC Compressor
Clutch does not engage under normal
operating conditions, refer to Section
1B
for procedure to check refrigerant pres-
sure.
0 If refrigerant pressure is normal, replace
the Pressure Cycling Switch.
A: A/C COMPRESSOR CLUTCH TEST
Measure: VOLTAGE
At:
Ale COlVlPRESSOR CLUTCH
(Disconnected)
Conditions:
lgnition Switch:
RUN (Engine need not
be running)
0 A/C Mode: NORM
@ Pressure Cycling Switch Connected
0 Temperature Outside Car: Above 60 OF
(16°C)
(Continued in next column) (Continued
from previous column) (Continued
from previous column)
Measure
Between Correct I For Diagnosis I 1. Check for open HTR-AIC Fuse or open
BRN
(50) wire.
I (DK GRN' I Battery I See 1 I & Ground
@ If voltages are correct but clutch does not
engage, replace the Compressor Clutch.
1. Check that Ale Nigh Pressure Cut-Out
Switch is closed (see schematic).
If it is
open, replace it. Check for an open in the
LT BLU (67) wire and the DK BLU (67)
wire. Check for an open in the DK GRN
(59) wire.
2. Check for an open in the BLK (150) wire.
ID* GRN)
& A (BLK)
B: AIG COMPRESSOR FUNCTION
CONTROL TEST - -
Measure: VOLTAGE
At:
A/C CONTROL HEAD
Conditions:
@ Ignition Switch: RUN
@ AIC Mode: NORM
0 Temperature Outside Car: Above 60OF
(16OC)
Battery
Measure
Between
I ~~~~~~ I For Diagnosis I
See 2
(BRN' &
Ground
If voltages are correct, check for an open
in the LT GRN (66) wire.
C (LT GRN) &
Ground The
compressor for the
air conditioning sys-
tem is belt driven by the engine through the
Compressor Clutch. The clutch allows the com-
pressor to be disengaged when
air conditioning
is not required or to remove the
air conditioning
load from the engine when necessary.
-
Battery Operation
of the compressor depends on the
particular
AIC mode selected by the driver.
When the
AIC Mode Selector Switch is in MAX,
NORM, BI-LEVEL, or DEF, battery voltage is
applied through the
HTR-AIC Fuse and Ale
Control Head Selector Switch to the remaining
circuits.
See
1
Battery
V6VIN S
For vehicles equipped with the V6 VIN S
engine, the path to the
AIC Compressor Control
Relay
is through the AIC Pressure Cycling
Switch and the
AIC Nigh Pressure Cut-Out
Switch which are both normally closed. The
AlC Pressure Cycling Switch opens when
refrigerant pressure drops to a point near the
level where the evaporator may begin to ice.
It
closes again when additional cooling is
required. This action causes the compressor to
cycle on and off. The
AIC High Pressure Cut-
Out Switch opens when refrigerant pressure is
too high for normal operation.
Replace AIC
Control
Head

AIR CONDITIONING: BLOWER CONTROLS
C67, ELECTRONIC
SYMPTOM TABLE 4: BLOVVER MOTOR TEST
Measure: VOLTAGE
At: BLOWER MOTOR CONNECTORS
(Disconnected)
Conditions:
r Ignition Switch: RUN
NC Mode: VENT
e Blower Switch: HI
I C2:zt;)d& I Battery I See 1 I
Measure
Between
& Battery See 2
If the voltages are correct, but the Blower
does not
run, install a new Blower Motor.
Correct
Voltage
1. Check PPL (65) wire for an open. If wire is
good, do Tests B and
D.
For
Diagnosis
1 2. Check BLK (150) wire for an open and
ground
6112 is clean and tight.
B: BLOWER HIGH SPEED RELAY TEST
(TABLE
11
I D(RED) Ground & I Battery I See 1 I
Measure: VOLTAGE
AT: BLOWER HIGH SPEED RELAY
CONNECTOR (Disconnect)
Conditions:
ignition Switch: RUN
r AIC Mode: VENT
r Blower Switch: HI
I (PPL) & 1 Battery
Ground I See 2 I
For
Diagnosis
Measure
Between
a If voltages are correct, proceed to Table 2.
1. Check RED (2) wire for an open back to
F'usible Link B.
2. Check PPL (101) wire for an open. If wire is
good, do Test
C.
3. Check ORN (52) wire for an open. If wire is
good, do Test
D.
Correct
Voltage
(ORN) &
Ground
(Continued on next page)
Battery
See 3

AIR CONDITIONING: BLOWER CONTROLS
(Continued from previous page)
B: BLOWER HIGH SPEED RELAY TEST
(TABLE
2)
Measure: RESISTANCE
AT: BLOWER
HIGH SPEED RELAY
CONNECTOR (Disconnected)
Conditions:
o lgnition Switch: OFF
o Negative Battery
Terminal: DISCONNECTED
( Measure I Correct I For 1
Between I Resistance I Diagnosis
B (BLK) & 0 ohms
Ground
Ground
3 ohms
0 If voltages in Table 1 and resistances in
Table 2 are correct, but Blower Relay does
not operate or runs
all the time, replace
the Blower Relay.
1. Check BLK (150) wire for an open.
6: BLOVVER RESlSTORS TEST D: BLOVVER SWITCH TEST (TABLE 1)
2.
Check PPL (65) wire for an open. If wire is
good, recheck measurements made in
Test A.
Measure: RESISTANCE
At: BLOWER RESISTORS CONNECTOR
(Disconnected)
Condition:
Ignition Switch: OFF
Measure
Between
A&C
C&D
D&B
OR CONNECTOR
(Disconnected)
lgnition Switch: RUN
AIC Mode: VENT
Blower Switch: M2
If
resistances are correct, Blower Resistors
are operating normally. Return to Symptom
Table.
1. Install new Blower Resistors.
Correct
Resistance
1.5 rt. 1 ohm
0.7
+ .5 ohm
0.2
rt. .l ohm
D (LT BLU) &
Ground
For
Diagnosis
See 1
See 1
See 1
If all voltages are correct, go to Table 2.
1. Check BRNIWNT (64) wire for an open. If
wire
is good, do Test E. (see schematic).
2. If battery voltage is present, check for a
wire to wire short to voltage. If wire is good,
replace the Blower Switch.
3. Check TAN (63) wire for an open.
4. Check LT BLU (72) wire for an open.
5. If voltage is present at terminal A but is
not present at either terminals C or
D,
check the BRNIWHT (64) wire for an open
between the Blower Resistor terminal A
and the AlC Control Head terminal E.
Battery See 4 and 5

AIR CONDITIONING: BLOWER CONTROLS
C67, ELECTRONIC
(Continued from previous page)
GRNIBLK (990) wire. If wire is good, do
Test
E.
5. Check for open in BRNNHT (64) wire. If
wire is good, do Test
E.
6: A/C CONTROL HEAD LED AND PANEL
LIGHT TEST
Measure: VOLTAGE
At:
A/C CONTROL HEAD CONNECTORS
(Connected)
Conditions: Ignition Switch: RUN
@ AIC Mode: VENT
* Light Switch: PARK
Light Dimmer Setting:
Full Brightness
I (GRY) & I Battery / See 2 1 Ground
Measure
Bemeen
T (BRN) C1 &
Ground
Light Dinimer Setting: Minimum
Brightness
Correct
Voltage
Battery
If voltages are correct, but Panel Lights
or LED Indicators do not light or dim,
replace the
AlC Control Head.
1. Check BRN (9) wire for an open.
For
Diagnosis
See 1
(GRY) '
Ground
61. If Blower Switch Indicator does not light,
check LT GRN (991) wire for an open. If
wire is good, replace
AlC Control Read.
* If any individual LED Mode Indicator does
not light, replace
AlC Control Head.
CIRCUIT OPERATION
The Blower Motor is a variable speed motor
which runs at a speed proportional to the
applied voltage. The higher the voltage applied
to the motor, the faster the speed.
When the Ignition Switch is
in RUN, battery
voltage is applied to the Low Blower Relay
through the
NTR-AIC Fuse.
With the Mode Selector in OFF, the Low Blower
Relay coil is grounded through the GRY wire and
the
A/C Control Head. The relay operates, its con-
tacts open, and the voltage to the Blower Switch
is removed. No voltage is supplied to the Blower
circuits. When any other mode except OFF is se-
lected, the Low Blower Relay is deenergized and
voltage is applied to the Blower Switch and
Blower Resistors.
With the Blower Switch in LO, voltage is
applied through
all Blower Resistors to the con-
tacts of the Blower High Speed Relay, and the
Minimum
Panel Light Voltage
- -
Blower Motor. The blower runs at low speed.
As the Blower Switch is moved through posi-
tions
M1 and M2, the switch bypasses some of the
Blower Resistors allowing more voltage to be ap-
plied to the Blower Motor which will increase its
speed.
See
3
When
the Blower Switch is in HI, voltage is
applied through the ORN (52) wire to the coil of
the Blower Nigh Speed Relay. The Blower Nigh
Speed Relay operates, removing the Blower Re-
sistors from the circuit.
Battery voltage is then applied directly to the
Blower Motor through the relay contacts and
the motor runs at maximum speed.
The battery voltage at
t
Control Read is also applied to the Blower
Switch Indicator and the Mode Selector Indica-
tors through the LT GRN (991) wire and Mode
Selector Switch. When the light switch is
turned to the PARK or HEAD position, bat-
tery voltage is applied to terminal T of the
AIC
Control Head which enables the Solid State
dimmer. The brightness of the LED Indicator
will then be det
terminal R. The volt
trolled by the panel
sets the brightness level of the panel lights and
LED Indicators in the
AIC Control Head.
1 2. Check GRY (8) wire for an open. I
3. Go to 8A-12, Light Switch Details for
diagnosis.

AIR CONDITIONING: COMPRESSOR CONTROLS
667, ELECTRONIC:
(Continued from previous page)
SYSTEM CHECK TABLE SYSTEM DIAGNOSIS
times
ACTION
1. Turn the Ignition Switch to RUN and start the
engine
Set the
A/C Mode to OFF then to MAX
2. Alternately select OFF and MAX several
Clutch plate movement can be seen on the front
1 ISOLATION TEST (TABLE I) of the compressor pulley
1 I If the clutch does not engage, proceed to step 4 (
EXPECTED RESULT
A click can be heard when the clutch engages
Verify that the clutch engages in MAX
If the clutch operates as expected, continue to
1 St€??J 3 I
V6 VIN S
r Use the isolation Test below to choose the
proper diagnostic tests.
Tests follow the isolation Test.
3. Select MAX mode to engage clutch Check
that air from the coolant fan can move
freely through condensor
Feel the input (cool) and output (warm) pipes to
the compressor
If there is not a wide temperature difference after
the compressor has run for several seconds, see
Section
1B for refrigerant and Compressor
diagnostics
4. Turn off the ignition
Check the refrigerant charge, according to the
procedures in Section
1B
If the refrigeramt charge is low, follow the
procedures in Section
1B for refrigerant diagnosis
If the refrigerant charge is normal, isolate the
conditions using the procedures which follow in
the System Diagnosis
(ISOLATION TEST (TABLE 1) continued on
facing page)
Measure: VOLTAGE
At: AIC COMPRESSOR CONTROL RELAY
CONNECTOR (Disconnected)
Conditions:
ignition Switch: RUN (Engine need
not
be running)
c A/@ Mode: NORM
* Temperature Outside Car: Above 60°F
(16°C)
Refer to System Diagnosis when a result is not normal. Measure
Between
C (PNKIBLK)
& Ground
Correct
Voltage
Battery
For
Diagnosis
Check GAGES
Fuse and PNKi
BLK (39) wire
for an open

(Continued on next page)
AIR CONDITIONING: COMPRESSOR CONTROLS
C67, ELECTRONlG
(ISOLATION TEST (TABLE 1) continued A: ECM COMPRESSOR CONTROL TEST A:
ECM COMPRESSOR CONTROL TEST
If action is correct, do Test A.
from
facing page)
(TABLE 2)
Measure: RESISTANCE
At: ECM CONNECTOR (Disconnected)
Conditions:
r Ignition Switch: OFF
.a Negative Banery Terminal
Disconnected
E (DK GRNI
WHT) &
Ground
(TABLE 1)
Measure: VOLTAGE
At: ECM CONNECTOR (Disconnected)
Conditions:
r Ignition Switch: RUN (Engine not
running)
AIC Mode: NORM
AIC Compressor Control Relay
Connected
Temperature Outside Car: Above 60°F
(I 6°C)
For
Diagnosis
See 1
Measure
Between
B9 on Conn 61
(GRY) &
Ground
Battery
.a If
resistance is correct proceed to Table 3.
1. Check that Power Steering Switch is closed.
If switch is open, replace it. Check for an
open in the GRY (901) wire and
BLKIWHT
(450) wire.
Correct
Resistance
0 ohms For
Diagnosis
See 1
See 2
Measure
Behnreen
B8 on Conn Cl
(DK GRNi
WHT) &
Ground
A2 on Conn
61
(LT BLU) &
Ground
Check
DK
GRNNHT
(59) wire for
an open.
If wire is good,
do Test C
If voltages are correct proceed to Table 2.
1. Check for open in DK
GRNNHT (59) wire.
2. Check for open in LT BLU (905) wire. If wire
is good, replace
AIC Compressor Control
- Relay.
Correct
Voltage
Battery
Battery
If
voltages are correct leave
AlC Com-
pressor Control Relay Connector
disconnected and go to Table
2.
lSOLATlON TEST (TABLE 2)
Connect: FUSED JUMPER
At:
AIC COMPRESSOR CONTROL RELAY
CONNECTOR (Disconnected)
Conditions:
Ignition Switch: RUN (Engine need
not be running)
r A/C Mode: NORM
.a Temperature Outside Car: Above 60°F
(1 6°C)
Jumper
Between
E (DK GRNI
WHT) & A
(DK GRN)
Correct
Action
Clutch
Engages
For
Diagnosis
Do Test B