1973 OPEL GT-R maintenance

9A-2 1973 OPEL SERVICE MANUALHEATER SYSTEM
- GT
CONTENTS
Subject
DESCRIPTION AND OPERATION:
Flow-ThroughVentilationSystem................................
Heater System Description............................................
HeaterSystemOperation................................................
DIAGNOSIS:
Heater and Defroster........................................................
MAINTENANCE AND ADJUSTMENTS:
Control
CableAdjustment..............................................
MAJOR REPAIR:
Removal
81 Installation Instrument Panel
FreshAirOutlet..............................................................
Removal
& Installation Kick Panel Fresh
AirOutlet..........................................................................
Removal&InstallationBlowerSwitch......................
Removal&InstallationHeater......................................
Removal&InstallationDefrosterOutlet..................
Removal
81InstallationHeaterValve........................
SPECIFICATIONS:
Specifications......................................................................Page No.9A-29A-29A-49A-49A-49A-59A-59A-59A-59A-09A-99A-9
DESCRIPTION AND OPERATION
FLOW-THROUGH VENTILATION SYSTEMA separate ventilation system for direct intake of
outside air is controlled by two plastic fresh air inlet
nozzles in the side kick panels and two lever operated
inlet nozzles located on either end of the instrument
panel assembly.
The air allowed to enter the passenger compartment
will exit through outlets on both sides of the back
glass. See Figure 9A-1.
HEATER SYSTEM DESCRIPTIONThe GT heater system consists of two components
assemblies: (1) heater assembly, and (2) control as-
sembly. The heater assembly consists of the heater
housing and air valves; heater core and blower motor
and fan assembly.Figure
9A-1 GT Air Flow
The flow of air enters the car through the cowl;
passes through the blower fan, through or around the
heater core, past the air inlet door and is then di-
rected to either the floor outlets or defroster outlets
or both depending on the position of the defroster
door.

9A-4 1973 OPEL SERVICE MANUAL
Figure 9A-4 Heater Control
Blower Switch - This switch actuates blower motor
to low or high blower speed.
HEATER SYSTEM OPERATION
To operate heater proceed as follows:
1. Position air inlet, heater-defroster control as
desired.
White arrow head pointing down--air out of heater
outlets. White arrow head pointing up--air out of
defroster outlets.
Between lower and upper position--air to both heater
and defroster outlets.
2. Position temperature control as desired to increase
or decrease temperature of air flow.
3. Position blower switch as desired to operate
blower at low or high speed.
Dlid3NDSlS
HEATER SYSTEM TROUBLE DIAGNOSIS
TROUBLE
Temperature of heated air at outlets too low.
CAUSE AND CORRECTION
Check radiator cap for proper sealing action-- re-
place if necessary.
Check for adequate coolant supply. If level is down,
correct cause of coolant loss and refill radiator.
Inspect hose for kinks--relieve kink or replace hoses.
Check thermostat operation by measuring tempera-
ture of coolant at radiator. Temperature should be
within 5 degrees F. of thermostat rated value (189
degrees F.).
Check that air doors and water temperature control
valye are operating properly.
Check for plugged heater core--backflush heater core
as necessary.
TROUBLE
Inadequate defrosting action.
CAUSE AND COiiRECTlON
Examine heater-defroster door for proper operat-
ions--adjust bowden cable as required so that door is
fully closed in FULL DEFROST position.
Check that air hoses connecting to defroster outlets
are secure.
Check for air leaks around edges of heater air dis-
tributor housing--seal leaks as necessary with body
sealer. Check for body air leaks and seal as necessary
with body sealer.
TROUBLE
Blower inoperative.
CAUSE AND CORRECTION
Check blower fuse--replace if necessary, fuse position
3 - amperage 8.
Check wiring for open circuit--correct as required. Inspect for defective component (i.e., blower switch
or blower motor)--replace or repair as necessary.
MAINTENANCE AND ADJUSTMENTS
CONTROL CABLE ADJUSTMENT
Adjustment of control cables is accomplished by po-
sitioning of the jacket or sheath of the control cable
as held by the clamps on the control assembly and
heater case.
To adjust control cables, loosen clamps and move
cable sheath in or out as required to obtain full travel
of lever or of door or both.

SA-10 1973 OPEL SERVICE MANUAL
HEATER SYSTEM
OPEL 1900 - MANTA
CONTENTS
Subject
DESCRIPTION AND OPERATION:
Heater System
. . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Function of the Heater
and Ventilation System
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .DIAGNOSIS:
HeaterSystem
Trouble
Diagnosis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .MAINTENANCE AND ADJUSTMENTS:
ControlCable
Adjustment
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .MAJOR REPAIR:
Removal&InstallationHeaterHousing,. . . . . . . . . . . . . . . . . . . .Removal
& Installation Defroster Jets. . . . . . . . . . . . . . . . . . . . . .Removal
81 Installation Heater Control Housing . . . .
Removal
& Installation Heater Motor. . . . . . . . . . . . . . . . . . . . . . . .SPECIFICATIONS:
Specifications
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page No.
9A-10
9A-11
9A-11
PA-12
PA-12
9A-13
9A-14
9A-15
9A-16
DESCRIPTION AND OPERATIONHEATER SYSTEM
The temperature of the air entering the vehicle is
regulated by the heater valve and the blower. The
distribution of this air is controlled by the heater air
distributor housing under the instrument panel.
Moving the upper control lever from the left towards
the right opens the heater valve. This lever regulates
the flow of coolant through the heater core and
thereby increases or decreases the air temperature
proportionate to its travel. See Figure 9A-30.
Figure 9A-30 Heater Control AssemblyThe connectors for water inlet and outlet are located
on the left side of the heater core, viewed in driving
direction. The coolant flow is shown in the drawing.
See Figure 9A-3 1.
Figure
9A-31 Coolant Flow in Heater Core
Due to the separation of the inflowing and outflow-
ing water in the heater core, an even heating of the

9A-i2 1973 OPEL SERVICE MANUAL
Check that air doors and water temperature control
valve are operating properly.
Check for plugged heater core-backflush heater core
as necessary.TROUBLEInadequate defrosting action.
CAUSE AND CORRECTIONExamine heater-defroster door for proper operation.
Adjust bowden cable so that door is fully closed in
FULL DEFROST position.
Check that air hoses connecting to defroster outlets
are secure.
Check for air leaks around edges of heater air dis-
tributor housing. Seal leaks, as necessary, with bodysea@. Check for body air leaks and seal, as neces-
sary, with body sealer.
TROUBLEBlower inoperative.
CAUSE AND CORRECTIONCheck blower fuse. Replace, if necessary, fuse posi-
tion 4
- amperage 15.
Check wiring for open circuit. Correct, as required.
Inspect for defective component, (i.e., blower switch
or blower motor)
- replace or repair as necessary.
MAINTENANCE AND ADJUSTMENTS
CONTROL CABLE ADJUSTMENTAdjustment of control cables is accomplished by po-
sitioning of the jacket or sheath of the control cable,
as held by the clamps on the control assembly and
heater case or by loosening screws and slidingbowden wire to obtain desired door or water valve
position.
MAJOR REPAIR
REMOVING AND INSTALLING HEATER HOUSING
Removal1. Unscrew hood lock together with ground wire(ground wire only on vehicles with radio interference
suppression). See Figure 9A-33.
Figure 9A-33 Hood Lock Attachments
2. Unscrew heater housing cover.
3. Pull hose of windshield washer system off jet and
take jet out of housing cover.
4. Unscrew bowden control wire from heater valve.
5. Unscrew heater housing from dash panel and pull
it off carefully. See Figure 9A-34.
Figure 9A-34 Heater Housing Attachments
6. Remove water hoses from heater core and pull
heater core out of heater housing. See Figure
9A-35.

REFRIGERANT COMPONENTS
ALL MODELS
CONTENTS
Subject
DESCRIPTION AND OPERATION:
FundamentalPrinciplesofRefrigeration..................
Description of Air Conditioning Components
..........DIAGNOSIS:
GeneralInformation..........................................................
Leak Testing
System1........................................................
Functional Testing System............................................
DiagnosisGuide..................................................................
MAINTENANCE AND ADJUSTMENTS:
General Service Information and
Safety Precautions;........................................................
Charging
andDischargingSystem..............................
AddingOiltotheSystem................................................
Flushing the System........................................................
MAJOR REPAIR:
Removal and Installation Compressor
Opel1900.Manta........................................................
GT
........................................................................................
Removal and Installation Condenser
Receiver-Dehydrator
Assembly
- GT.................................................................
Receiver-Dehydrator
.Opel 1900.Manta................GT..................................................
Removal and Installation Evaporator and
Expansion Valve
- Opel 1900.Manta....................
GT......................................................
Disassembly and Reassembly of Clutch Drive
Plate
andShaftSeal....................................................
Disassembly and Reassembly of Pulley Assembly
and Coil and Housing Assembly..............................
Disassembly and
Reaissembly of Internal
Parts of Compressor and Leak Testing
Compressor..............................................................................
SPECIFICATIONS:
Specifications........................................................................Page No.
9B-18
98-33
98-38
98-39
98-39
90-40
98-41
98-41
9B-47
98-48
98-48
98-56
98-62
90-4990-58
98-52
98-59
98-63
98-67
98-69
98-82REFRIGERANT COMPONENTS ALL MODELS
96-17

REFRIGERANT COMPONENTS ALL MODELS9s. 41
BIower Operating Normal Check for the following:Restriction or leakage in air ducts, A/C outlets not
opening.2. Do not carry cylinder in passenger compartment
of car.3. Do not subject cylinder to high temperatures.
MAINTENANCE AND ADJUSTMENTS4. Do not weld or steam clean on or near cylinder.
5. Do not fill cylinder completely.
GENERAL SERVICE INFORMATION AND SAFETY
PRECAUTIONS6. Do not discharge vapor into area where flame is
exposed or directly into engine air intake.
General InformationAll subassemblies are shipped sealed and dehy-
drated. They are to remain sealed until just prior to
making connections, and should be at room tempera-
ture before uncapping. This prevents condensation of
moisture from air that enters the system.
All precautions should be taken to prevent damage
to fittings or connections. Even minute damage to a
connection could cause it to leak. Any fittings with
grease or dirt on them should be wiped clean with a
cloth dipped in alcohol.
Do not clean fitting or hoses with solvents because
they are contaminants. If dirt, grease or moisture
gets inside the pipes or hoses and cannot be removed,the pipe or hose is to be replaced. Use a small amount
of clean refrigeration oil on all tube and hose con-
necting joints, and lubricate the
“0” ring gasket with
this oil before assembling the joint. The oil will help
in effectitig a leak-proofjoint and assist the
“0” ring
to slip into the proper location without being cut or
damaged. Always use new
“0” rings.
When tightening joints, use a second wrench to hold
the stationary part of the connection to prevent
twisting and to prevent hose kinking. Kinked hoses
are apt to transmit noise and vibration. Tighten all
connections in accordance with recommended
torques (see Division VI, Specifications).7. Do not expose eyes to liquid
- WEAR SAFETY
GOGGLES whenever discharging, charging or leak
testing system.
CHARGING AND DISCHARGING SYSTEMRemoval of any part in the refrigerant circuit will
require discharging of the entire system.
Discharging the System1. Remove caps from gauge fittings on the compres-
sor adapter fitting on the compressor.
2. With both valves on manifold gauge set (J-5725-
04) closed (clockwise), attach manifold to the com-
pressor adapter fitting on the compressor, using
J-5420 valve adapter at suction gauge fitting and
J-9459 valve adapter at discharge gauge fitting. See
Figure
9B-41.3. Fully open high pressure valve on manifold gauge
set to allow escape of refrigerant from system
through the manifold gauge set and out the center
fitting and hose. (Place end of hose in clean container
to collect oil loss due to rapid discharge of system).
4. When hissing ceases, indicating all refrigerant
has escaped, close high pressure valve on manifold
gauge set by turning valve clockwise.
Do not connect receiver-dehydrator assembly until
all other connections have been made. This is neces-
sary to itisure maximum moisture removal from sys-
tem.It is important that air conditioning hoses do not rest
on or contact body sheet metal except where neces-
sary. Because of the high frequency at which the
compressor operates, the passenger compartment is
susceptible to transfer of noise.
Evacuating the SystemWhen the refrigeration system is depressurized and
opened for service, some air will enter the lines, re-
gardless of how quickly openings are capped. In
or-der to remove this air and as much as possible of the
moisture it contains, the complete system must be
evacuated. Evacuating is merely the process of
removing all air from the system, thereby creating a
vacuum in the system.
Safety PiecautionsThe following safety precautions should always be
followed~,when servicing refrigerant charged compo-nents:Under no circumstances should alcohol be used in
the system in an attempt to remove moisture,
regard-less of the successful use of alcohol in other refrigera-
tion systems.
Preparations for Evacuating Complete System
1. Do not leave Refrigerant-12 cylinder uncapped.
1. Check the low pressure gauge for proper calibra-

System controls are the AIR knob controlling the
three speed blower motor switch and the TEMP
knob which controls the setting of the thermostatic
switch. When operating this system, the heater must
be off for maximum cooling.DIAGNOSIS
TROUBLE DIAGNOSIS GUIDE
Air Knob
Insufficient CoolingTurning the AIR knob clockwise operates the three-
speed blower motor.CHECK AIR FLOW9B-90 1973 OPEL SERVICE MANUAL
AIR CONDITIONER SYSTEM
OPEL 1900
- MANTA
CONTENTS
Subject
DESCRIPTION AND OPERATION:
General Description of System
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...”Operation of Controls
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . .DIAGNOSIS:
DiagnosisGuide. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..“................... . . . . . . . . .MAINTENANCE AND ADJUSTMENT:
Adjustment of Thermostatic Switch
. . . . . . . . . . . . . . . . . . . . . . . . .MAJOR REPAIR:
Removal81InstallationBlowerSwitch. . . . . . . . . . . . . . . . . . . . . .Page No.
9B-90
9B-90
9B-90
9B-91
98-92Removal
& Installation Temperature Control Switch
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . * . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Removal
& Installation Resistor Assembly. . . . . . . . . . . . . .Removal
& Installation Blower Motor Assembly . .
SPECIFICATIONS:
Specifications
.,...,,.,,..~.,.,..,,......,.,....,.,........,......,........ ,, . . . . . . .
98-92
98-92
98-92
98-96
DESCRIPTION AND OPERATION
GENERAL DESCRIPTION OF SYSTEMThe air conditioner is intended to give maximum
cooling comfort within the vehicle. To do this, care-
ful attention must be given to the following Sections.
The system operates on recirculated air only and is
entirely independent of the vehicle heater.
Temp KnobThis knob may be regulated to control the degree of
cooling desired. Fully clockwise provides maximum
cooling; however, turning the knob to the center de-
tent position provides adequate cooling for highway
operation.
When maximum cooling is required, outside air
should not be admitted to the car.
Recirculated inside air is drawn into the unit, passed
through the evaporator core and into the car through
the adjustable outlets in the evaporator case.
Operation of ControlsWhen the unit is set for maximum cooling and the
vehicle is being driven continuously at highway
speeds or at elevations of
4,OOC!ft. or more, there is
a possibility of the formation of ice on the evaporator
core fins.

AIR CONDITIONER SYSTEM -OPEL 1900 - MANTA9B- 91FAN DOES NOT RUN Correct electrical fault.
FAN RUNS
- Check air velocity.
NOT OK Clean evaporator inlets.
Clean evaporator core.
Clean evaporator outlets.
OK Check refrigeration (refer to Refrigeration
Diagnosis Guide).
MAINTENANCE AND ADJUSTMENTS
ADJUSTMENT OF THERMOSTATIC SWITCHThe system makes use of a thermostatic switch with
a self-supporting air sensing capillary. This capillary
controls the switch by sensing the temperature of the
air leaving the evaporator fins.
Checking for Proper Operation
I. Install the gauge set and set up the vehicle as
described under FUNCTIONAL TESTING SYS-
TEM iti Refrigerant Components Section.
2. Movement of the temperature control knob
should result in a definite change in suction pressure
and cycling of the compressor clutch.
3. If compressor continues to operate regardless of
the knob adjustment, it indicates that the switch
points are fused, which will lead to evaporator
freeze- up. The switch should be replaced.
Adjusting Switch
If, after ihe foregoing checks, the switch seems to be
operating correctly, adjust for proper setting if neces-
sary, as
~follows:1. Set up car as described in FUNCTIONAL
TESTING SYSTEM in Refrigerant Components
Section.2. The suction side of the system, read on the low
pressure gauge, should pull down to the pressure
shown in the chart in SPECIFICATIONS in Refrig-
erant Components Section.
3. Remove the face plate retaining screws and
remove face plate assembly noting the position of the
air sensipg capillary so that it can be reinstalled in
the same location as when removed. See Figure 98.170. ,:Figure
98.170 Location of Air Sensing Capillary
4. Remove the thermostatic switch retaining screws
and remove switch. Remove the non-metal end plate
from the switch to gain access tq the switch adjusting
screw. Check the screw for stripped or otherwise
damaged threads.
5. If the low side pressure
was less than the pre-
scribed pressure at the end of each cooling cycle, turn
the adjusting screw a partial turn clockwise. See Fig-
ure
9B-171.Figure 9B-17 1 Adjusting
Thkmosfatic Switch
6. If the pressure was more than the prescribed
value, turn the adjusting screw counter-clockwise.
7. Reinstall switch end plate and install switch in
face plate. Install face plate on ,evaporator assembly
assuring that the air sensing
c&pillary has been re-
placed properly.
8. Check system performance. Fffurther adjustment
is needed, repeat steps 3 thru 7 until the correct
pressure is reached.
Do not attempt to run a performance test with the
face plate and switch removed
,from the evaporator
assembly
- inaccurate reading, will result. Always
replace the switch and face plate assemblies before
checking the system performance.