PONTIAC FIERO 1988 Service Repair Manual

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)

AIR CONDITIONING: BLOWER CONTROLS I z
660, MANUAL
(A: BLOWER MOTOR TEST continued from
facing page)
I Measure I Correct For
Between
I Voltage I Diagnosis
I (PPL) & 1 Battery I See 1 ( Ground
1 (yi,"g C2 I Battery 1 see 2 1
e If the voltages are correct but the blower
does not run, install a new Blower Motor.
1. Check the PPL
(65) wire for an open. If the
wire is good, go to Test B and Test D.
2. Check the BLK (150) wire for an open and
that ground
6112 is clean and tight (see
schematic).
B: BLOWER HIGH SPEED RELAY TEST
(TABLE
1)
(Continued from previous column)
Measure: VOLTAGE
At: BLOWER RELAV CONNECTOR
(Disconneded)
Conditions:
@ lgnition Switch: RUN
e AlC Mode: VENT
r Blovver Svvitch: HI
@ If all voltages are correct, go to Table 2.
1. Check RED (2) wire for an open back to
Fusible Link B.
2. Check ORN (52) wire for an open. If wire is
good, go to Test D.
3. Check PPL (65) wire for an open between
the Blower Nigh Speed Relay Terminal B
and the Blower Resistors Terminal B. If
wire is good, go to Test C.
Measure
Bemeen
(RED) &
Ground
A (ORN) &
Ground
B: BLClVVER HIGH SPEED RELAY TEST
(TABLE
2)
Measure: RESISTANCE
At:
BLClWER HIGH SPEED RELAY
CONNECTOR
(Disconnected)
Conditions:
lgnition Switch: OFF
Negative Battery Terminal:
DISCONNECTED
Correct
Voltage
Battery
Battery
I 'g;dd& I o ohms I see I I
~easure I Correct
Between
For
Diagnosis
See 1
See 2
Blower Switch: LO
B (PPL) & Less than 3
Ground See
2
For
B (PPL) &
Ground
a If all results in Table 1 and Table 2 are
correct, but Blower Relay does not oper-
ate or Blower runs
all the time, replace the
Blower Relay.
1. Check the BLK (150) wire for an open.
2. Check the PPL (65) wire for an open. If wire
is good, go to Test A.
I I Resistance
6: BLOWER RESlSTORS TEST
Diagnosis
Battery
See 3
D: BLOWER SWITCH TEST (TABLE 1)
Measure: VOLTAGE
At:
BLOVVER RESISTORS CONNECTOR
(Disconnected)
Conditions:
r lgnition Switch: RUN
AlC Mode: VENT
Blower Switch: LO
Measure:
RESISTANCE
At: BLOWER RESISTORS
(Disconnected)
Condition: lgnition Switch: OFF
I Measure I Correct I For I
Between 1 Voltage I Diagnosis For
Diagnosis
See 1
See 1
Measure
Between
A&C
C&D
I A (YEL) & 1 Battery I See 1 & 6 / Ground
0.7 rt 5 ohm
If the results are correct, Blower Resistors
are operating normally. Return to Symptom
Table.
1. Install new Blower Resistors.
Correct
Result
1.5 rt 1 ohm
0.2rt1 ohm
( @ Blower Switch: M1 I
C (TAN) &
Ground
(D: BLOWER SWITCH TEST (TABLE 1)
continued on next page)
(Continued in next column)
I&
0 Volts See 2

AIR CONDITIONING: BLOWER CONTROLS
C60, MANUAL
(D: BLOWER SWITCH TEST (TABLE 1) con- (Continued
from previous column) (Continued
from previous column)
tinued on previous page)
D: BEClVVER SWITCH TEST (TABLE 2)
(TAN) '
Ground
D (LT BLU) &
Ground
Between I Voltage I Diagnosis
Battery
Volts
Measure: VOLTAGE
At:
BLIWEW HIGH SPEED RELAY
CONNECTOR
(Disconnected)
, Conditions:
ignition Switch: RUM
A/C Mode: VENT
' @ Blower Switch: M2
See 3 & 6
See 4
Blower Switch: M2
~easure I Correct
E: AIC MODE SELECTOR TEST
At: A/C CONTROL HEAD CONNECTOR
(Connected)
Conditions:
lgnition Switch: RUM
Ground 0
Volts
D (LT BLU) 8
Ground
For
A (ORN) &
ground
Between I Voltage I Diagnosis
If all voltages are correct, go to Table 2.
1. Check YEL (51) wire for an open.
2. If voltage is present, check TAN (63) wire
for a wire to wire short to voltage. If wire
is good, replace the Blower Switch.
3. Check the TAN (63) wire for an open.
4. If voltage is present, check LT BLU (72)
wire for a wire to wire short to voltage.
If
wire is good, replace the Blower Switch.
5. Check Lt BLU (72) wire for an open.
6. If battery voltage is not present at terminals
A,
G or D, go to Test E. If voltage is present
at one or more of the terminals, replace the
Blower Switch.
Battery
e A/c Mode: OFF
I (BRN) & I Battery
Ground I see 1 /
If voltages are correct, Blower Switch is op-
erating normally. Return to Symptom
Table.
1. If voltage is present, check ORN (52) wire
for a wire to wire short to voltage. If wire is
good, replace Blower Switch.
2. Check ORN
(52) wire for an open. If wire is
good, replace Blower Switch.
Battery
See 5
& 6
Measure I Correct
See 2
For
I e AIC Mode: All positions except OFF I
D (BRNNHT)
& Ground
I (BRNIWHT) I Battery & Ground I see 3 /
(Continued in next column)
Volts
@ If all voltages are correct, check the BRNI
WNT (64) wire for an open. If wire is good
replace the Blower Switch.
1. Check BRN (50) wire for an open back to
HTR
A/C Fuse.
2. If voltage is present, check BRNIWNT
(64) wire for a wire to wire short to volt-
age. If wire is good, replace
A/C Control
Head.
3. If battery voltage is present at terminal E
but is not present at terminal D, replace
the
AIC Control Head.
See 2 The
Blower Motor speed is controlled by the
Blower Switch in the
AIC Control Head. With the
switch in the LO position, all of the Blower Re-
sistors are in the circuit with the motor so that it
runs slowly. In the
M1 and M2 positions, the
Blower Switch bypasses some of the Resistors, in-
creasing the Motor speed.
Voltage is applied to the Blower Motor
through the contacts of the Blower Nigh Speed
Relay. When the Blower Switch is in the
HI
position, battery voltage is supplied through
the ORN wire to the coil of the Blower High
Speed Relay. The Relay is energized and its
contacts supply battery voltage directly to the
Blower Motor from Fusible
Link B.
When the Mode Selector is in the OFF posi-
tion, no voltage is applied to the Blower Switch
and Motor so the Blower does not run. In all
other positions, the Blower will operate as
described.
(Continued in next column)

- AIR CONDITIONING: COMPRESSOR CONTROLS
660, MANUAL, V6 VIN S

AIR CONDITI0N"rG: COMPRESSOR CONTROLS
660, MANUAL, V8 VIN F, V8 VlN 8
FUSE - BLOCK -
AlC - CONTROL
HEAD
-
OPEN 20-28 PSI
CLOSES 45.51 PSI ELECTRONIC
CONTROL
- MODULE (EGMI . . SOLlD STATE
DO NOT MEASURE
RESISTANCE
CUT-OUT SWITCH
OPENS ABOVE 2960
kPa (430PSI)
B CLOSES BELOW 1379 kPa (200PSI)
A/C COMPRESSOR
CLUTCH
-

AIR CONDITIONING: COMPRESSOR CONTROLS
660, MANUAL, V8 VlN E
FUSE - BLOCK -
PRESSURE ELECTRONIC
CONTROL
MXE (ECM) OPEN 20-28 PSI
CLOSES 45-51 PSI SOLID STATE
DO NOT MEASURE
RESISTANCE
AlC HIGH El PRESSURE
CUT-OUT SWITCH OPENS ABOVE 2960 kPa (430PSI)
8 CLOSES BELOW 1379 kPa 12flflPSIl

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)

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

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)