check engine PONTIAC FIERO 1988 Service Repair Manual

Page 1324 of 1825


CRUISE CONTROL 2
I Slide Cruise Control Switch momentaril~ to RIA I Car should accelerate to former set s~eed I
(Continued from facing page)
--
While cruising, accelerate, then remove foot I car should coast back to set speed
from accelerator
Release Cruise Switch
back to ON
Tap brake pedal
I While cruising, tap Cruise Switch to RIA I Car should increase 1 mph for each tap, up to I
Car should hold new faster speed
Car should coast slower (Cruise disengages)
tap
until 25 mph is reached when cruise
Control will not o~erate I
While cruising, tap Set button
1 Slide Cruise Switch to OFF ten
taps, then system must be reset to a new
speed
Car speed should decrease by
1 mph for each
I Cruise Control turns off 1
0 Refer to System Diagnosis when a result is not normal.
SYSTEM DIAGNOSIS
@ Use the isolation Test below to choose the
proper diagnostic tests.
@ Tests follow the Isolation Test.
Note: Do not press both the SET and RIA
Switches at the same time while the
engine is running. If the Quick Checker
displays
a short light, release the
switches immediately. Shorts can
damage the Quick Checker.
lSOLATlON TEST
Connect: QUICK CHECKER (J-34185, SPECMO QC-3 OR EQUIVALENT) or VOLT-OHMMETER
At: CRUISE CONTROL MODULE CONNECTOR (Disconnected)
Conditions:
@ Ignition Switch: RUN
Test with Quick Checker
(J-34185 or equivalent) or Digital Meter
Test Condition
Cruise Switch OFF
(ISOLATION TEST continued on next page)
All Lights Off
With Quick
Checker,
Correct Response
-
20 VDC
20 VDC
For
Different
Response, Do
Test:
B
Without Quick Checker,
Using a Digital Meter
A&J
M&J
Meter
Range
200 ohms
0 volts
0 volts
Connector
Terminals
J & Ground
A
Correct
Response
0 ohms

Page 1325 of 1825


CRUISE CONTROL
(ISOLATION
Test
2 3
4
5
6
7
If all
TEST continued from previous page)
Condition
Cruise Switch ON
Cruise Switch ON, Set Switch
pressed
Cruise Switch
in RIA
Cruise Switch ON, drive wheels
turned by hand
Run engine for one minute, then
turn it off. With Ignition Switch in
RUN, and holding Cruise Switch
in
RIA, press Set Switch, wait for
Servo to pull
in and release Set
Switch
Quick Checker not connected
the responses were correct, replace Cruise
With Quick
Checker,
Correct Response
ONIOFF Light On
BRK Light On
VENT Light On
VAC Light On
SPS Light On
RA Light Off
SC Light Off
SC Light On
VAC
& SNORT Lights Off
ONIOFF Light On
RA Light On
VENT & SNORT Lights
Off
VSS Light flashes On and
Off
Vacuum holds the servo
all theway in
-
Control Module and check
Without Quick Checker, For
Using
a Digital Meter Different
Meter
Range
20 VDG
20 VDC
200 ohms
200 ohms
200 ohms
20 VDC
20 VDC
20 VDC
200 ohms
20 VDC
20 VDC
200 ohms
20VDC
Connector Terminals
A&J
G&J
C&J
K&J
F&N
M&J
L&J
L&J
K&J
A&J
M&J
C&J
A&D
Response,
Correct Do
Response Test
Battery voltage B
Battery voltage C
30 to 55 ohms D
30 to 55 ohms E
15 to 25 ohms F
0 volts A
0 volts
A
Battery voltage G
30 to 55 ohms N
Battery voltage A
Battery voltage
I
30 to 55 ohms J
Pulses between
approximately battery
voltage and less than
7 K, L
volts
Connect fused jumper from
CtoMandfromKtoL
before operating switches
200ohms 1 F&J
for proper operation.
Vacuum holds the servo
all the way in M
Over range N

Page 1334 of 1825


BRAKE VVARNlNG SYSTEM
TROUBLESHOOTING HINTS
0 Try the following checks before doing the
System Diagnosis.
Check the GAGES Fuse and PNKIBLK
(39) wire by observing the VOLTS or
SERVICE ENGINE SOON Indicator with
the Ignition Switch in RUN and the engine
OFF.
0 Go to System Check for a guide to normal
operation.
0 Go to System Diagnosis for diagnostic tests.
SYSTEM CHECK
Use the System Check Table as a guide to
normal operation.
e Refer to System Diagnosis for a list of symp-
toms and diagnostic steps.
SYSTEM CHECK TABLE
RUN position to
BULB TEST
COMPONENT LOCATION Page-Figure
.................. Brake Fluid Level Switch. ......... Below brake fluid reservoir 201-16-A
..................... Fuse Block. Behind
LH side of IIP, below light switch. ...... 201-10-A
................. Ignition Switch. Behind IIP, on
top side of steering column ...... 201- 9-A
Parking Brake Switch.
............ In console, at base of parking brake ........... 201-12-D
................... Release Relay Taped
to IIP harness, behind RH side of IIP. .... 201-13-A
................ (2100 (42 cavities) LR
front of dash, left of brake master cylinder .. 201- 0-A
........................... S204. IIP harness, behind instrument cluster. ........ 201-10-A
.......................... ............... S228. IIP harness, above Fuse Block. 201-10-A
SYSTEM DIAGNOSIS
0 Diagnostic steps for the symptorns listed'in
the following table are listed after the table.
A: BRAKE INDICATOR REMAINS ON
WITH THE
IGNITION SWITCH IN
RUN AND THE PARK BRAKE OFF
(TABLE
1)
SYMPTOM TABLE
A BRAKE Indicator remains on with the
Ignition Switch
in RUN and the park
brake off
B BRAKE Indicator lights with the park
brake applied, but does not light when
brake fluid level is low
C BRAKE Indicator does not light at all
D BRAKE Indicator lights with the Igni-
tion Switch in BULB TEST, but does not
light when the park brake is applied
E BRAKE Indicator lights with the park
brake applied, but does not light when
the Ignition Switch is in BULB TEST
Refer to System Diagnosis when a result is
not normal. Disconnect:
CONNECTOR
At: BRAKE FLUID LEVEL SWITCH
Conditions:
0 Ignition Switch: RUN
0 Park Brake: OFF
Pressure Warning
If the result is correct, refer to Section
5 to
test the Brake Hydraulic System.
Replace the Brake Fluid Level Switch if
the Brake Hydraulic System is OK.
1. Go to Table2.

Page 1351 of 1825


AIR CONDITIONING: BLOWER CONTROLS
C60, MANUAL
TROUBLESHOOTING
HINTS
Try the following checks before doing the
System Check.
1. Check the HTR A/C Fuse by visual inspection.
2. Check that ground
6112 is clean and tight.
3. Check that Blower Motor connectors and
Blower Relay are mated correctly and firmly
seated.
Go to the A/C System Check in 8A-62 for a
guide to normal operation.
Q Go to System Diagnosis for diagnostic tests.
SYSTEM DIAGNOSIS
Do the tests listed for your symptom in the
Symptom Table below.
Q Tests follow the Symptom Table.
SYMPTOM TABLE
SYMPTOM
Blower runs all the
time (Ignition OFF)
Blower run
all the
time (Ignition OFF)
Blower will not run
in any mode
No Lo speed
operation
COMPONENT LOCATION Page-Figure
Blower High Speed Relay.
......... RH front of dash, near Blower Motor ..........
Blower Motor (With Ale) .......... RH front of dash. ..........................
Blower Resistors (With AIC) ....... RH front of dash, behind strut tower ..........
Fuse Block. ..................... Behind LH side of IIP, below light switch. ......
Fusible Link B (VIN E). ........... Lower RH side of engine, at Starter Solenoid. ...
Fusible Link B (VIN F) (VIN 8) ..... Lower RH side of engine, at Starter Solenoid. ...
Fusible Link B (VIN S). ........... Lower RH side of engine, at Starter Solenoid. ...
(2102 (4 cavities) ................. Center front of dash. .......................
6115 (1 cavity). .................. Center front of dash. .......................
(2202 (1 cavity) .................. Behind. center of IIP, near control head. ........
6112 (VIN E) ................... Rear of LN cylinder head. ...................
6112 (VIN F) (VIN 8) ............. Rear of LH cylinder head. ...................
6112 (VIN S). ................... Rear of LH cylinder head. ...................
Slll ........................... Engine harness, RH rear of engine compartment
S117 (VINE)
.................... Engine harness, RH front of dash. ............
S117 (VIN F) (VIN 8) ............. Engine harness, top center rear of engine. ......
S119. .......................... AIC harness, RH rear of engine compartment ...
DO TEST
B : Blower High
Speed Relay Test
E:
AIC Mode
Selector Test
A: Blower Motor Test
E: A!C Mode Selector
Test
C: Blower Resistors
Test (Continued
from previous column)
A: BLWER MOTOR TEST
Measure: VOLTAGE
At: BLOWER MOTOR CONNECTORS
(Disconnected)
Conditions:
Ignition Switch: RUN
Q NC Mode: VENT
Blower Switch:
HI
If your symptom does not appear in the SY~P- (A: BLOWER MOTOR TEST continued on fat- tom Table, perform all of the tests. ing page)
Hi speed only
Blower runs in Lo at
M1 or M2
No Hi speed
operation
B: Blower High
Speed Relay Test
D: Blower Switch
Test
D: Blower Switch
Test
B: Blower High
Speed Relay Test
D: Blower Switch
I Test 1
(Continued in next column)

Page 1358 of 1825


AIR CONDITIONING: COMPRESSOR CONTROLS
660. MANUAL
TROUBLESHOOTING
HINTS
Try the following checks before doing the Sys-
tem Check
.
1 . Check HTR-A/C Fuse by visual inspection .
2 . Check that the A/C Compressor Clutch con-
nector is firmly seated
.
3 . Check that ground 6112 is clean and tight .
Go to System Check for a guide to normal
Cornpressor Control operation
.
Go to System Diagnosis for Compressor Con-
trol diagnostic tests
.
SYSTEM CHECK
Complete the AIC System Check in Section
8A-62 as a guide to normal operation of the
AIC Systern .
Use the System Check Table as a guide to
normal operation of the Compressor Controls
.
COMPONENT LOCPaTlON Page-Figure
.... ..................... AIC Compressor Clutch (VIN E)
Top RH front of engine 201-
4-A
Ale Compressor Clutch (VIN F) (VIN
..................... ............................ 8) Top RH front of engine 201- 6-A
.... ...................... AlC Compressor Clutch (VIN S)
Top LH front of engine 201- 0-B
..... AIC Compressor Control Relay
LH rear corner of engine compartment. on relay
................................. bracket 201- 0-A
A/C High Pressure Cut-Out Switch
....................... (VIN E)
Top RH front of engine. on rear of AIC
.............................. compressor 201- 4-D
Ale Nigh Pressure Cut-Out Switch
................. (VIN F) (VIN 8) Top RN front of engine. on rear of AIC
.............................. compressor 201- 6-C
AIC High Pressure Cut-Out Switch
....................... (VIN S)
Top LH front of engine. on rear of AIC
.............................. compressor 201- 0-B
Diode
.......................... Inside AIC Compressor Clutch connector ....... 201- 0-B
Electronic Control Module (ECM)
... Behind RH side of I/P ...................... 201-12-B
Fuse Block
...................... Behind LH side of IIP. below light switch ....... 201-10-A
............ Power Steering Switch
Lower LR front corner of engine compartment.
.......................... on steering unit 201- 0-A
.................. Pressure Cycling Switch ........... On side of AlC accumulator 201-14-A
.. el00 (42 cavities) ................ LH front of dash. left of brake master cylinder
201- 0-A
........................ 6102 (4 cavities) ................. Center front of dash 201-14-A
......... C202 (1 cavity) .................. Behind center of IIP. near control head
201-14-C
6112 (VINE)
................... Rear of LH cylinder head .................... 201- 3-C
6112 (VIN F) (VIN 8)
............. Rear of LH cylinder head .................... 201- 7-C
G112 (VIN
S) .................... Rear of LH cylinder head .................... 201- 0-C
6118 (VIN S) .................... Rear of RH cylinder head .................... 201- 1-C
S111 ........................... Engine harness. RN rear of engine compartment 201- 1-A
S117 (VIN
F) (VIN 8) ............. Engine harness. top center rear of engine ....... 201- 7-A
S120
........................... Engine harness. RH front ofdash ............. 201- 2-A
........... S143 (VIN S) .................... Engine harness. center front of dash
201- 1-A
S175 (VIN S) .................... Engine harness. lower LH front of dash ........ 201- 0-A
(Continued on next page)

Page 1359 of 1825


AIR CONDITIONING: COMPRESSOR CONTROLS OD D
C60. MANUAL I I
(Continued from previous page) COMPONENT LOCATION
.......................... $177. Engine harness,
top RN front of engine ........ 201- 5-A
.......................... $204. I/P harness, behind instrument cluster. ........ 201-10-A
SYSTEM CHECK TABLE
I ACTION I EXPECTED RESULT I
1. Turn the Ignition Switch to RUN and start the engine A click can be heard when the clutch engages
Move the
A/C Mode Selector to OFF then to MAX
2. Move the Mode Selector between OFF and MAX several times Verify
that the clutch engages in the MAX position
I I Clutch plate movement can be seen on the front of the comgressor pdey I
I I If the clutch does not engage, proceed to step 4
If the clutch operates as expected, continue to step
3
3.
Put the Mode Selector in MAX to engage clutch Check
that air from the coolant fan can move freely through condensor
1 1 Feel the input (cool) and output (warm) pipes to the cornpressor I
I
If there is not a wide temperature difference after the compressor has run
for several seconds, see Section 1B for refrigerant and compressor diag-
nostics
4. Turn off the ignition If the
refrigerant charge is low, follow the procedures in Section 1B for
Check the refrigerant charge, according to the procedures in Section
1B refrigerant diagnosis
If the refrigerant charge is normal, isolate the conations using the pro-
cedures which follow in the System Diagnosis

Page 1360 of 1825


AIR CONDITIONING: COMPRESSOR CONTROLS I i
660, MANUAL B
2
SYSTEM DlAGNOSlS
V6 VIN S
0 Use the Isolation Test below to choose the
proper diagnostic tests.
0 Tests follow the Isolation Test.
ISOLATION TEST (TABLE 1)
At: AIC COMPRESSOR CONTROL RELAY
CONNECTOR (Disconnected)
0 lgnition Switch: RUN
(Engine need not be running)
0 AIC Mode: NORM
0 Temperature Outside Car: Above 60 OF
Measure
Between Correct I For Diagnosis / Voltage
I
I - I
Check
C
(PNKIBLK) GAGES Fuse
BLK
(39) wire
for
an open
Check DK
I 0 If voltages are correct, leave AIC Corn-]
I I
E (DK GRNl
WNT) &
Ground
I
.#
pressor Control Relay connector
disconnected and go to Table
2.
ISOLATION TEST (TAB!-E 2) u (Continued -from previous column) I I I I I
Battery
Connect: FUSED JUMPER
At:
AlC COMPRESSOR CONTROL RELAY
CONNECTOR (Disconnected)
Conditions:
lgnition Switch: RUN (Engine need not
GRNIWNT
(59) wire for an
open. ~f wire is
good, do Test
C
be running)
0 AIC Mode: NORM
0 Temperature Ot~tside Car: Above 60°F
Correct Result For Diagnosis
1 ::zn 1 1 1
If action is correct, do Test A.
E (DK GRNI
WHT' & A
(DK GRN)
A: ECM COMPRESSOR CONTROL
TEST (TABLE
1)
Measure: VOLTAGE
At: ECM CONNECTOR (Disconnected)
Conditions:
0 lgnition Switch: RUN
(Engine need not be running)
AIC Mode: NORM
0 AIC Compressor Control Relay:
CONNECTED
Temperature Outside Car: Above 60°F
116°C)
Clutch
engages
[ B8 on Conn 1 I I
Do Test B
Measure
Between
I C1g,";,"N1 I Battery I See 1 I
I Ground I
(Continued in next column)
Correct
Voltage
1 ~~~~~~) 1 Battery 1 See 2
& Ground
If the voltages are correct, proceed
to
Table 2.
For Diagnosis
1. Check for an open in the DK GRNlWNT
(59) wire.
2. Check for an open in the LT BLU (905)
wire. If the wire
is good, replace the AlC
Com~rc!ssor Control Relay.
A: ECM COMPRESSOR CONTROL
TEST ('FABLE
2)
Measure: RESISTANCE
At: ECM CONNECTOR (Disconnected)
Conditions:
0 lgnition Switch: OFF
Negative Battery Terminal
I Disconnected
Measure I Correct I For Diagnosis I I Between Resistance
B9 on
Conn
C1 (GRY) & 0 Ohms See 1
Ground
0 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
(Continued on next page)

Page 1361 of 1825


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

Page 1362 of 1825


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)

Page 1363 of 1825


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

Page:   < prev 1-10 ... 301-310 311-320 321-330 331-340 341-350 351-360 361-370 371-380 381-390 ... 400 next >