1973 OPEL MANTA water

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

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.).

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.

Figure SA-35 Heater Core
Installation
1. Apply sealing compound between heater housing
and dash panel.
2. Install heater core into heater housing and attach
water hoses. See Figure 9A-35.
3. Instaii heater housing to dash panel. S,ee Figure9A-44.
4. Install bowden control wire to heater valve.
5. Install windshield washer jet into housing cover
and attach hose.
6. Install heater housing cover, and seal with a seal-
ing compound.
7. Install hood lock, together with
grc’und wire
(ground wire only on vehicles with radio interference
suppression).
REMOVING AND INSTALLING
DEFROSTE+lOUTLETS
Removal
1. Pull out heater switch lever. See Figure 9A- 36.
2. Remove instrument cover.
3. Unscrew bowden control wires from heater valve
and air distributor housing and pull out heater con-
trols.
4. Remove glove compartment.
HEiATER SYSTEM - OPEL 1900 - MANTA9A. 13Figure SA-36 Removing Heater Switch Lever
5. Remove radio.
6. On right side, viewed in driving direction, remove
air distributor housing attaching screws. See Figure9A-37
Figure SA-37 Air Distributor Housing Attaching
SCWWS7. On left side, viewed in driving direction, remove
upper attaching screw through opening for heater
control housing and lower attaching screw below
instrument panel. See Figure 9A-38.
8. Pull air distributor housing off dash panel

HEATER SYSTEM. OPEL 1900. MANTA9A- 15
Figure 9A-4 1 Bowden Wire Attachment
Figure SA-42 Control Wire
to Distribution? DoorAttachmentA
- Yellow Wire
B
- Grey Wire
C
- Brown Wire
6. Remove heater control housing.
Installation1. Install heater control housing,
2. Install wires onto blower switch. See Figure 9A-
53.Figure 9A-43 Blower Switch Wires
A
- Yellow Wire
B
- Grey Wire
C
- Brown Wire
3. Attach bowden control wire to air distribution
flap. See Figure 9A-42.
4. In engine compartment, attach bowden control
wire to heater valve. See Figure 9A-41.
5. Install two (2) sheet metal screws for control hous-
ing attachment. See Figure 9A-40.
6. Install instrument panel cover.
7. Adjust bowden control wires.
REMOVAL AND INSTALLATION OF HEATER
MOTOR
1. In engine compartment, remove five (5) shroud
cover attaching screws. See Figure 9A-44.
2. Carefully remove cover
3. Pull water hose off windshield wiper jet.
4. Disconnect wires to heater motor. For this pur-
pose, disconnect multiple plug connection on left
side of shroud. See Figure 9A-45.
5. Remove three (3) heater motor attaching screws.
See Figure 9A-46.
6. Take off motor.

98.18 1973 OPEL SERVICE MANUAL
DESCRIPTION AND OPERATION
FUNDAMENTAL PRINCIPLES OF REFRIGERATION
We all know what air conditioning does for us, but
very few understand how or why it works. An air
conditioner is functionally very similar to a refrigera-
tor, so let’s take a look at refrigeration. A refrigerator
is a simple mechanism which, surprisingly enough,
works quite a bit like a tea-kettle boiling on a stove.
That may sound far-fetched, but there is more
similarity between the two than most of us would
suspect. In fact, a modern refrigerator can make ice-
cubes and keep food cool and fresh only because a
liquid called the refrigerant boils inside the freezer.
Of codrse everyone knows a boiling tea-kettle is
“hot” and a refrigerator is “cold”. However, this is
where most of us are apt to get confused. We usually
think of “cold” as a definite, positive condition. Ac-
tually though, there is no such thing as “cold”. The
only way we can define it is in a rather negative sort
of way by saying “cold” is simply the lack of heat
just as darkness is the lack of light. We can:t make
things cold directly. All we can do is remove some
of the heat they contain and they will become cold
as a result. And that is the main job of any ice-box
or refrigerator. Both are simply devices for removing
heat.
All substances contain some heat. Theoretically, the
lowest temperature that any substance could obtain
is 459 degrees Fahrenheit below Zero. This may be
called “Cold”, and anything warmer than this con-
tains heat. Since man has never succeeded in getting
all the heat out of an object, we must think about the
transfer of heat from one object to another when
talking about controlling temperatures.
Figure
96-1 Transfer of Heat
Transfer of HeatThe only thing that will attract heat is a colder ob-ject.
:Like water, which always flows down-hill, heat
always flows down a temperature scale
- from a
warm level down to a colder one. When we hold our
hands out toward the fireplace, heat flows from the
hot fire out to our cold hands (Fig.
9B-1). When we
make a snowball, heat always flows from our warm
hands to the colder snow. In an ice-box, the ice al-
ways is colder than the stored food, so heat naturally
is drawn out of the warm food by the colder ice.
Measurement of HeatEveryone thinks he knows how heat is measured.
Thermometers are used in most: homes. Whenever
we speak of temperature from now on, we will mean
Fahrenheit. They can tell how hot a substance is, but
they can’t tell us everything about heat.
Figure
98-2 Applied Temperature Alone is Not the
Sole Measurement of Heat
When we put a tea-kettle on a stove, we expect it to
get hotter and hotter until it finally boils. All during
the process, we can tell exactly how hot the water is
by means of a thermometer (Fig.
9B-2). However,
our thermometer will show us that the flame is just
as hot when we first put the tea-kettle on the stove
as it is when the water finally boils. Why doesn’t the
water boil immediately then? Also, why does it take
longer to boil a quart of water than a cupful? Obvi-
ously temperature isn’t the only measurement of
heat.
Even though heat is intangible, it can be measured by
quantity as well as intensity. It is recognized that
thermometers indicate only the intensity of heat. The
unit for measuring quantity of heat is specified as
that amount necessary to make 1 pound of water 1
degree warmer (Fig.
9B-3). We call this quantity of
heat a British Thermal Unit. Often it is abbreviated
to Btu.
Perhaps we can get a better idea of these two charac-

REFRIGERANT COMPONENTS ALL MODELS9s. 19
Figure 98.3 Effect of One B.T.U. on One
Pc’und of
water
teristics of heat if we think of heat as a sort of color-
ing dye. If we add one drop of red dye to a glass of
water, it will turn slightly pink. Another drop will
make the water more reddish in color (Fig.
9B-4).The more drops of dye we add, the redder the water
will get. Each drop of dye corresponds to 1 Btu and
the succeedingly deeper shades of red are like in-
creases in temperature.
Figure
98-4 Addition of B.T.U. Heats Water
It may seem a little puzzling to talk about beat in a
story on air conditioning but, when you stop to
think about it, we are handling heat exclusively. Al-
though we ordinarily think of an air conditioner as
a device for making air cold, it doesn’t do that di-
rectly. What it does is take heat away from the in-
coming air and transfer that heat outside the vehicle.
We know now that cold is nothing more than the
absence of heat, and that heat always flow from a
warm object to a colder one. We also have
:a clearer
idea of how heat is measured.
From everything we’ve learned about heat
EO far, it
seems to behave in a perfectly normal manner. Yetsometimes heat will disappear without leaving a sin-
gle clue.
Ice vs. Water for CoolingEtery once in a while in the old days, the ice-man
would forget to refill the ice-box. Occasionally, as the
last sliver of ice melted away, somebody would come
up with a bright idea. He would remember that the
water in the drain-pan always felt ice-cold when he
had emptied it other times. So, he would get the
thermometer out and check its temperature. Sure
enough, it usually was about as cold as the ice. Why
not put the drain-pan back in the ice compartment
to keep things cold until the iceman returned the
next day
It was a good idea. but it never worked. For some
strange reason the ice-box never stayed cold. The
drain water soon got quite warm and in a couple of
hours, the butter in the ice-box would begin to melt,
the milk would start to sour, and the vegetables
would wilt.
Why did this happen? The drain water was only a
few degrees warmer than the ice yet it didn’t draw
nearly as much heat out of the stored foods. How-
ever, the difference between the behavior of cold
drain water and ice is the real secret as to how any
refrigerator works and we can easily learn the an-
swer by using an ordinary thermometer.
When we put a drain pan full of cold water into the
ice compartment, we expect the heat to flow from the
warm foods to the colder water. Remember, that
heat always flows from a warm object to a colder
object and when we add heat to water, it gets
warmer. Each Btu of heat added to a pound of water
makes it one degree warmer.
Figure 98.5 Melting Ice Remains at 32 Degrees