1988 PONTIAC FIERO air conditioning

INTRODUCTION
OTHER INFORNlATlORl
Body Part Names
Refer to figure 4 for the correct body part
names.
VIN References
If schematics for more than one variation of
an engine type-V6, for example--are shown,
then the schematics will be labeled with VIN
designations to distinguish the variations.
Service Parts Identification Label
To aid service and parts personnel in identi-
fying options and parts originally installed. a
Service Parts Identification Label has been
REAR
PANEL
placed in the car. See the General Information
Section OA of the Chassis Service Manual for
Figure 4 - Body Part Names
the location of the label and the definition of
the option codes.
Abbreviations
AIC - Air Conditioning
BCbl - Body Computer Module
ECM
- Electronic Control Module or Engine
Control Module
IIP
- Instrument Panel
RH
- Right Hand. as seen from driver's seat
LH
- Left Hand
Not Used
- The connector cavity has no func-
tion.

THROTTLE BODY INJECTION: V8 VIN E
GOLD START AND EMISSION CONTROL
EXHAUST GAS
AIR CONDITIONING: COMPRESSOR CONTROLS

MULTI-PORT FUEL INJECTION: V8 VIN 8
COLD START AND EMlSSlON CONTROL
ASSEMBLY LINE DIAGNOSTIC LINK
EXHAUSTGAS
RECIRCULATION
AIR CONDITIONING:
- - - -

AIR CONDITIONING: ALL SYSTEMS OD P
SYSTEM CHECK
Use the System Check Table as a guide to
normal operation.
All of the checks can be
pedormed without the use of tools or dis-
assembly of components.
Even though one or
more checks may not give
a normal result, complete the entire System
Check to reveal ail symptoms which may
exist.
SYSTEM CHECK TABLE
(SYSTEM CHECK TABLE continued on facing page)

AIR CONDITIONING: ALL SYSTEMS
(SYSTEM CHECK TABLE continued from facing page)
Set Temperature lever to COLD
13. OFF
If all of the above steps can be completed as described, the Air Conditioning and I-leating system is operating normally.
Blower and Compressor turn off 8A-63,64 Blower and Compressor Controls
8A-66,67 Blower and Compressor Controls

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)