1988 PONTIAC FIERO Service Repair Manual

1B-22 AIR CONDITIONING
HEATER UPPER MODE CLOSED
POSITION DOOR POSITION POSITION
I SIDE WINDOW DEFOG
DEFROSTER
A BLEED
HEATER AIR
OFF AND HEATER MODES
SlDE WINDOW DEFOG
HEATER AIR
BI-LEVEL MODE FULL
COLD POSITION
FULL HOT POSITION
(ALL AIR AROUND
(ALL AIR THROUGH
HEATER CORE) HEATER CORE)
TEMPERATURE
TEMPERATURE
COlUTROL
MAX,NORM AND VENT MODES
SlDE WINDOW DEFOG
DEFROSTER AIR
HEATER BLEED
DEFROST MODE
5201 26-1 8
Figure 19 Air Flow Direction In Each Operating Mode

AIR CONDITIONING "18-23
10. CONTROL
14. LOWER MODE
DIAPHRAGM
16. DEFROST DIAPHRAGM
17. UPPER MODE
DIAPHRAGM
18. RECIRCULATION
5. TO WATER VALVE 19. lfVPUT (VIOLET)
6. A/C ELECTRICAL 20. DEFROST (BLUE)
21. LOWER MODE (TAN)
22. UPPER MODE (RED)
8. RECIRCULATION
DIAPHRAGM J~OZ~~-IB-F
Figure 20 AIC Vacuum Diagram
NG LlCbUlB LINE
Remove or Disconnect
1. Discharge A!C system.
2. Disconnect liquid line couplings at evaporator
and condenser connections.
3. Remove clip holding line to right frame rail.
4. Remove liquid line.
lnstall or Conne&
1. Reverse removal procedure to reinstall. Use
new O-rings lubricated with
525 viscosity
refrigerant oil.
2. Recharge and test system for proper operation.
COUPLED NC HOSE ASSEMBLY
Remove or Disconne&
lnstall or Conne&
1. Reverse removal procedure to reinstall. Use
new O-rings lubricated with
525 viscosity
refrigerant oil.
2. Recharge and test system for proper operation.
Remove or Disconnect
1. Discharge A!C system.
2. Disconnect electrical connection at pressure
cycling switch and remove switch.
3. Disconnect hose and evaporator fittings.
4. Loosen accumulator clamp-bracket screw.
5. Remove accumulator.
1. Discharge
NC system.
2. Disconnect hose assembly at accumulator, con- Install or Connect
denser, and at rear of c6mpressor head. 1. Reverse removal procedure to reinstall. Use
3. Disconnect clamps or straps that hold hose new
O-rings lubricated with 525 viscosity
assembly in position if so equipped, remove refrigerant
oil.
coupled hose assembly.
2. Recharge and test system for proper operation.

1B-24 AIR CONDPTIBNING
EVAPORATOR CORE
Remove QP Disconnect
1. Discharge A/C system.
2. Remove accumulator.
3. Remove two (2) screws and remove hi-blower
relay terminal.
4. Remove upper case screws.
5. Relocate wiring harness and remove dipstick.
6. Disconnect liquid line fitting.
7. Remove upper case and lift evaporator core out
of case (retain foam wedge).
Install or Connect
1. Reverse removal procedure to reinstall.
2. Recharge and test system for proper operation.
EVAPBRAWORCASE
Remove or Disconnect
1. Remove accumulator.
2. Remove blower motor.
3. Remove evaporator core.
Remove lower case to cowl screws (three driven from engine compartment, three driven from
interior).
Remove case from cowl.
Install or Connect
Reverse removal procedure to reinstall. Rein-
stall or replace gaskets, seal and sealant
removed during disassembly.
Recharge and test system for proper operation.
NG COMPRESSOR (TYPICAL)
Remove or Disconnect
1. Discharge A/C system.
2. Remove fitting block (coupled hose assembly)
bolt at rear of compressor.
3. Remove mounting bracket bolt(s) .
4. Remove drive belt (route lower loop behind har-
monic balancer to gain additional slack if
required).
5. Remove compressor. If complete compressor is
to be replaced, transfer usable switches, etc. to
new compressor.
Install or Connect
1. Reverse removal
procedure to reinstall. Use
new O-rings lubricated with
525 viscosity
refrigerant oil. Refer to Section
6B for drive belt
tension.
2. Evacuate and recharge system.
CONDENSER
a Remove or Disconnect
1. Discharge A/C system.
2. Disconnect coupled hose and liquid line fittings.
3, Remove screws retaining top radiator shield.
4. Remove top condenser retaining screws.
5. Carefully move (tilt) radiator rearward and lift
condenser out of radiator support.
6. Transfer brackets and mounts to new condenser
if replacement is necessary.
Install or Connect
1. Reverse removal procedure to reinstall. Use
new O-rings lubricated with
525 viscosity
refrigerant oil.
2. Recharge and test system for proper operation.
1. HEATER AND DEFROSTER ASSEMBLY
2. 1.4
N.m (12 LBS. IN.) INSTALL FIRST
3. CONSOLE ASSEMBLY
4.
1.4 Narn (12 LBS. IN.)
5. FLOOR OUTLET ASSEMBLY
Figure 21 Floor Outlet

1-STUD, PART OF CORE CASE ASM. 4-GASKET
2-A1 W IN LET ASM. 5-STUDS
PART OF CORE CASE ASSEMBLY I 3-R.W. SECT ION OF CASE REMOVABLE FOR 6-UPPER
SECTION OF CASE REMOVABLE FOR
HEATER CORE REPLACEMENT EVAPORATOR CORE REPLACEMENT
Figure 22 NC Module
and Case lnstallarion

1B-26 AIR CONDITIONING
7-FITTING (ENGINE)
13-PIPE ASM - INLET & 8-PIPE ASM - HTR INLET
OUTLET
9-A.I.R. PUMP BRACKET 14-GENERATOR
10-HOSE
- HTR OUTLET
15-GEN BRACKET 11-AIC EVAP TUBE ASM 16-GASKET
12-HOLES (SIDE RAIL)
Figure 23 NC Heater Hoses - V.I.N. S
2. A.I.R. VALVE
3. WATER VALVE
4. RADIATOR
5. AIC EVAPORATOR TUBE
Figure 24 NC Heater Hoses - V.I.N. E

1-PIPES (HTR MODULE)
2-CLAMP
3-HOSE
- OUTLET
4-HOSE
- INLET
5-VALVE ASM
6-HOSE
- HTR INLET
7-RADIATOR ASM
8-A/C EVAPORATOR TUBE ASM
9-PIPE ASM
- OUTLET
10-BOLTISCREW
11-HOLES (SIDE RAIL)
Figure 25 A/C Heater Hoses - V.I.N. F and 8

"1-28 AIR CONDITIORIBNG
Figure 26 AtC Control Wiring

AIR CONDITIONING 1B-29
1. 1.5 N.m (13 LBS. IN.) 8. BRACKET
2. SWITCH
9. AJC COMPRESSOR RELAY
3. ACCUMULATOR 10. BRAKE BOOSTER
4. HARNESS 11.
FUEL PUMP RELAY
5. BLOWER RESISTOR 12. FAN RELAY
6. HI BLOWER RELAY 13. AJC CONTROL
RELAY
7. BLOWER RELAY 14. BULK HEAD
J10255-18-F
Figure 27 A/C Module and Cowl Wiring