OPEL GT-R 1973 Service Manual

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.

HEATER SYSTEM. GT9A- 3
Figure 9A-‘2 Heater Assembly-Rear View
The heater-defroster air door directs the air to the
floor outlets, defroster outlets, or apportions the air
flow to both outlets depending on the position of the
door. A manual water valve regulates the flow of
coolant through the heater core, thereby varying the
temperature of the air flow past the core. The blower
motor is located in the forward portion of the heater
housing. See Figure 9A-2.
Opening and closing of the heater defroster air door
and manual water valve is accomplished by bowden
cables connected to the heater control. The heater
controls function as follows:
Air Inlet-Defroster Control (Upper Lever) Thiscontrol (See Figure 9A-4) opens and closes the air
inlet and heater-defroster air door which channels
the air flow to either the heater outlets or to defroster
outlets, or to both outlets simultaneously, depending
on the position of the control.
Temperature Control (Lower Lever)
- This lever
regulates the flow of coolant through the heater core
and the amount of air that can by-pass heater core
thereby increasing or decreasing the air temperature
proportionate to its travel (toward red square-warm;
toward blue square-cold). Unheated air may be cir-
culated through the car by leaving the temperature
control in the OFF position (blue square).
Figure 9A-3 Heater Assembly-Front View

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.

HEATER SYSTEM - GT9A- 5
MAJOR REPAIR
REMOVAL AND INSTALLATION INSTRUMENT
PANEL FRESH AIR OUTLET
Removal
1. Remove instrument panel cover assembly. Refer
to Group 1.
2. Snap grille out of outlet.
3. Remove knob from lever and remove outlet.
Installation
1. Install outlet and knob onto lever.
2. Snap grille into outlet.
3.
Install instrument panel cover assembly. Refer to
Group 1.
REMOVAL AND INSTALLATION KICK PANEL
FRESH AIR OUTLET
Removal
Using a screwdriver, carefully pry out outlet.
Installation
Install outlet.
REMOVAL AND INSTALLATION BLOWER
SWITCH
Removal
i. Remove instrument panel assembly. Refer to
Group 1.
2. Unscrew switch assembly from panel.
Installation
1. Screw switch assembly to instrument panel.
2. Install instrument panel assembly. Refer to Group
1.
REMOVAL AND INSTALLATION HEATER
Ramova!
1. Remove lower radiator hose, drain, and collect
coolant. 2. Detach coolant feed (A) and return (B) hoses, in
engine compartment from heater core. See Figure
9A-5.
Figure 9A-5 Heater Hose Connections
3. In engine compartment remove hood lock control
cable retaining clip and cable from lock bar. See Figure
9A-6.
Figure 9A-6 Hood Release Control Cable
4. Remove console shift cover between seats using
the following instructions:
a. Remove ash tray and remove two screws under it.

9A-6 1973 OPEL SERVICE MANUAL
b. Remove retaining screw in headlamp lever handle
and remove handle.c. Console cover is held in place by four push button
type studs, unsnap studs by prying cover up and
work cover upwards over shift lever and rubber shift
lever boot.
5. Remove left cover and right plug in instrument
panel cover and through openitigs remove instru-
ment panel attaching screws (points A and B). See
Figures 9A-7 and 9A-8. At this point it will be neces-
sary to lower the steering column, refer to Group 3
for this procedure.6. Remove two multiple wire plug connectors from
steering column harness.
7. Detach speedo cable
8. Remove
dir&ional signal flasher unit. See Figure9A-9.
Figure
9A-9 Directional Flasher Unit
9. Remove 6 instrument cluster retaining screws. See
Figure 9A-10.
Figure
9A-7 Instrument Panel Cover Screw Cover and
Plug LocationsFigure SA-10 Removing Instrument Cluster detaining
SCWWSFigure
SA-8 Location of Hidden Screws10. Grasp instrument cluster and pull straight back,
being careful of wires, etc. See Figure 9A-11.
11. Unscrew heater controls (A) and support bracket
(B). See Figure 9A-12.
12. Disconnect heater and defroster duct
hoses’frominstrument panel. See Figure 9A-13.

HEATER SYSTEM - GT9A. 7
13. Remove all screws from instrument panel pad-
ding and remove it from instrument panel. Arrow in
Figure
9A-14 show location at left side of dash panel
and windshield. Screws are located in same areas on
right side.
Figure 9A-1 1 Removing Instrument Cluster
Figure
9A-14 Instrument Panel Padding Screws
14. Remove one bolt at top of heater blower case and
two nuts from bottom of the case, and remove heater
blower and case assembly. See Figure
9A-15.
Figure 9A-12 Heater Control Screws and SupportBracket
Figure 9A-13 Heater and Defroster Duct Hoses Figure
9A-15
Location of Heater blower Case Boltand Screws
15. On removed heater assembly check relative posi-
tion of mixed air door so that on installation of unit hand control levers can be positioned according to
unit settings, either opened or closed position.

9A-8 1973 OPEL SERVICE MANUAL
Installation
1. Install heater blower and case assembly, securing
with one (1) bolt at the top and two (2) nuts from the
bottom. See Figure
9A-15.
2. Install instrument panel padding and connect
heater and defroster duct hoses, making sure hoses
are properly positioned and connected. See Figure
9A-16.
Figure 9A-16 Heater and Defroster Duct Hoses
3. Install support bracket (B) and heater control (A).
See Figure
9A-12.
4. Carefully push cluster back into instrument panel
housing, making sure electrical wires, etc., are not
pinched.
5. Install six (6) cluster retaining screws. See Figure
9A-10.
6. Install directional signal flasher. See Figure
9A- 9.
7. Attach speedometer cable.
8. Attach two (2) multiple wire plug connectors in
steering column harness.
9. Install steering column. Refer to Group 90.
10. Install instrument panel cover and attach
through openings (points A and B). See Figures
9A-7
and 9A-8.
11. Install right and left opening covers. 12. Install the console shift
cover
between the seats
using the following instructions:
a. Install console cover over shift lever and rubber
shift lever boot.
b. Install cover by pushing down until cover snaps into the four (4) push button type studs.
c. Install two (2) screws under ash tray opening and
install ash tray. 13.
In engine compartment, install hood lock control
cable to lock bar using retaining clip. See Figure
9A-
6.
14. Attach return hoses (B) and coolant feed hoses
(A) to heater core. See Figure
9A-5.
15. Attach lower radiator hose and add collected
coolant.
16. Check for proper operation and leaks in system.
REMOVAL AND INSTALLATION DEFROSTER
OUTLET
Removal
1. Remove instrument panel cover assembly. Refer
to Group 1.
2. Remove screws securing outlet to cover assembly.
Installation1. Install defroster outlet, securing with screws.
2. Install instrument panel cover assembly. Refer to
Group 1.
Figure 9A-17 Heater Valve

HEATER SYSTEM. GT9A- 9
REMOVAL AND INSTALLATION HEATER VALVE
Removal
1. Remove lower radiator hose and drain and collect
coolant.
2. Disconnect control cable.
3. Loosen heater hose clamps and remove valve from
hoses. See Figure 9A-17.SPECIFICATIONS
EngineRecommended Coolant
.__,.__...._...__.,.,...,......Thermostat Opens At (Degrees) F.
..__..___...Installation
1. Install valve into heater hoses and install hose
clamps.
2. Connect control cable.
3. Install lower radiator hose and add collected coo-
lant.
.....................................Ethylene-Glycol Base
...................................................................189Cooling
SystemCapacity(WithHeater)..........................................................................6Qt.BlowerMotorType
......................................................................................................12VDC
BlowerFanType
..................................................................................................SquirrelCage

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

HEATER SYSTEM. OPEL 1900. MANTA9A- 11air is attained, as the water does not cool down in the
second part of the core.
A Water Outlet
B Water Inlet
The center lever actuates the two-stage blower mo-
tor.Lever positions:
Left to Center
- Motor Switched Off
Right of Center
- Lo Blower
Right
- Hi Blower
The lower lever opens and closes the air door which
channels the air flow to either the lower heater out-
lets or to the defroster outlets.
In the left lever position, the air inlet is closed. Up
to the center position, the air is directed
t,o the lower
heater outlets.
When moving the lever from center position towards
the right, the air flow to the lower
heatezr outlets is
reduced and increased to the defroster
csutlets.With the lever in its right position, the air is directed
to the defroster outlets only. For windshield defrost-
ing, all levers have to be moved to the right.
FUNCTION OF THE HEATER AND VENTILATION
SYSTEMThe engine hood is provided with slots in front of the
windshield. The air is directed through the slots into
the heater housing located in the engine compart-
ment, flows into the air distributor housing, and
from there to the lower heater outlets and,/or defros-
ter outlets, depending on the position of the control.
The two-stage blower motor is arranged in the heater
housing above the heater core and actuated by the
center control. The blower motor draws in the air
entering through the slots, blows the air through the
heater core into the air distributor housin:?, and from
there to the lower heater outlets and/or defroster
outlets, depending on the position of the lower con-
trol. See Figure 9A-32.
The heater valve regulates the flow of coolant
through the heater core, thereby varying
t:he temper-
ature of the air flow past the core.
The ventilation of vehicle interior is completed by a
draft-free air circulation pattern. Vent
slots are ar-
ranged below the back window which
are: connected
through channels to the rear quarter
iside panel.
From here, the inside air escapes into
the! open. TheFigure
9A-32 Air Flow
head wind (caused by the car traveling down the
road) promotes this process so that there is always
fresh air in vehicle interior.
On the Model 54 Station Wagon, there will be no air
outlets in the rear. For adequate flow-through type
ventilation, it will be necessary to open a rear win-
dow.Aside from the fresh air admission through the
heater system, two fresh air inlet nozzles are ar-
ranged in the center of the instrument panel. These
nozzles can be turned to direct the air flow in the
desired direction. In addition, rotary flaps allow the
regulation of the entering air or to shut off the air
completely.
These nozzles admit unheated fresh air only and
operate independent of the heater and defroster sys-
tem.
DIAGNOSIS
HEATER SYSTEM TROUBLE DIAGNOSIS
TROUBLETemperature of heated air at outlets too low.
CAUSE AND CORRECTIONCheck 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.).