1973 OPEL GT-R maintenance

AIR CONDITIONER SYSTEM - GT96. 97
AIR CONDITIONER SYSTEM
GTCONTENTS
Subject
: DESCRIPTION AND OPERATION:
General Description of System
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Operation of Controls
. . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .DIAGNOSIS:
Diagnosis Guide
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .MAINTENANCE AND ADJUSTMENTS:
Adjustment of Thermostatic Switch
. . . . . . . . . . . . . . . . . . . . . . .MAJOR REPAIR:
Removal 8 Installation of Vacuum Switch.
Removal&InstallationBlowerSwitch. . . . . . . . . . . . . . . . . . . . . .Removal & Installation Temperature Control Switch
. . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . .
Removal&InstallationResistor Assembly. . . . . . . . . . . . . .Removal & Installation Blower Motor Assembly . .
SPECIFICATIONS:
Specifications
. . .
. . . . . . . . * . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page No.
9BL 97
9Bi 97
9BL 98
98: 98
9B: 99
9B; 99
9B- 99
98~10098-101
9B-104
DESCRIPTION AND OPERATIONAir Knob
GENERAL DESCRIPTION OF SYSTEMTurning the AIR knob clockwise operates the three-
speed blower motor.
The air &mditioner 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 @dependent of the vehicle heater.Temp Knob
Recirculated inside air is drawn into the unit, passed
through the evaporator core and into the car through
the adjustable outlets in the duct assembly.This knob may be regulated to cohtrol the degree of
cooling desired. Fully clock-wise provides maximum
cooling; however, turning the kndb to the center de-
tent position provides adequate cooling for highway
operation.
CONTROLSWhen maximum cooling is reqlired, outside air
should not be admitted to the car.
System c&trols are the AIR knob controlling the
three
spe&d blower motor switch and the TEMPWhen the unit is set for maximum cooling and the
vehicle is being driven continuously at highway
knob which controls the setting of the thermostaticspeeds or at elevations of 4,000 ft. or more, there is
switch. When operating this system, the heater musta possibility of the formation of ice on the evaporator
be off for maximum cooling.core tins.

98.98 1973 OPEL SERVICE MANUALDIAGNOSISTROUBLE DIAGNOSIS GUIDE
Insufficient Cooling
CHECK AIR FLOW
FAN 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 tins.
Checking for Proper Operation
1. Install the gauge set, and set up the vehicle as
described under FUNCTIONAL TESTING SYS-
TEM in 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 the 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 lowpressure gauge, should pull down to the pressure
shown in the chart in SPECIFICATIONS in Refrig-
erant Components Section.
3. Remove the duct assembly mtaining screws and
remove the duct assembly noting the position of the
air sensing capillary so that it can be reinstalled in
the same location as when removed. See Figure 9B-
190.Figure 98.190 Duct Assembly and Retaining Screws
Figure 9B-13 1 Duct Assembly
4. Remove the thermostatic switch retaining screws
and remove switch. Remove the non-metal end plate
from the switch to gain access to the switch adjusting
screw. Check the screw for stripped or otherwise
damaged threads.

RADIO. GT9c- 105
RADIO
GTCONTENTS
Subject
DESCRIPTION AND OPERATION: (Not Applicable)
DIAGNOSIS:
RadioTroubleDiagnosis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .MAINTENANCE AND ADJUSTMENTS:
Antenna Trimmer Adjustment
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .MAJOR REPAIR:
RemovingandInstallingRadio. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SPECIFICATIONS: (Not Applicable)
Page No.
9c-105
9C-106
9c-107
DIAGNOSIS
RADIO TROUBLE DIAGNOSISBecause radio problems are most often repaired at
United Delco authorized warranty repair stations,
the tendency for many dealer servicemen is to
remove the set when a problem is reported, without
any preliminary diagnosis. This results in a large
number of radios showing up as “NO TROUBLE
FOUND” units when received by the warranty re-
pair stations. This indicates that the trouble can
often be corrected without removal of the radio.
The inconvenience to an owner of driving without a
radio while his set is being serviced at a warranty
station can frequently be avoided if the following
quick checks are used to eliminate external radio
system :problems before removing the radio for re-
pair.
Always determine from the owner the exact nature
of the radio problem as an aid to diagnosis. Knowing
whether the condition is intermittent or constant,
whether it occurs with engine off or running, with
car stationary or moving, will help to pinpoint the
problem. Never turn on radio with speaker discon-
nected.
Radio Ii
Inoperative.1. Turn on the radio. The dial should light and a
thump should be heard from the speaker.a. If a thump is heard, go to Step No. 2 for antenna
check.b. If no thump is heard,
check the fuse.
(1) If fuse is bad, replace and try radio again. Race
engine and, if fuse blows again,‘remove the radio and
speaker assembly for repair by
4 trained radio techni-
cian.
(2) If fuse is good, check to
s&e that the speaker-to-
receiver interconnecting cable is connected securely.
If there is still no thump when the radio is turned on,
remove the receiver and speaker for repair.
2. Check the antenna by substituting with one held
out the car window.
a. If radio is still dead with substitute antenna,
remove the receiver and spea!er for repair.
b. If radio operates near normal with substitute an-
tenna, some part of the car antenna or lead-in is at
fault.
Radio Reception Is Weak1. Check to see if antenna trimmer is peaked.
a. Position antenna at a height of 31 inches.
b. Tune radio to weak station at or near 1400 KHz
on the dial, and turn volume control to maximum.

9C-106 1973 OPEL SERVICE MANUAL
c. Adjust trimmer screw for maximum volume.
d. If antenna trimmer does not have a definite peak, check for defective antenna by substitution.
2. Check that the speaker connection is plugged in
SXUdY.
3. If the radio is still weak, remove the receiver and
speaker assembly for repair.
Radio Is Noisy
1. Radio is noisy all the time:
a. Check for defective antenna by striking antenna
with hand. If static is heard while tapping, replace
antenna.
b. If antenna is not defective, remove receiver and
speaker for repair.
2. Radio is noisy only when jarred:
a. Check antenna as in Step No. 1 above.
b. Check speaker connection. If speaker connection is not at fault, remove receiver and speaker for re-
pair.
3. Radio is noisy when engine is running:
a. Check noise suppressor by substituting on genera-
tor with known good one.
b. Check to see that antenna is mounted securely,
grounding the antenna base to the fender. The an-
tenna lead-in wire is shielded and the shield should
have good ground connection at the receiver and the
antenna base.
c. Check for other car wiring, passing too close to
radio receiver case.
d. If engine noise is still present, remove receiver and
speaker for repair.
4. Radio is noisy when car equipment is operated,
such as directional lights or brake lights:
Check for defective antenna lead-in wire or, loose
antenna mounting, as in Step No. 3b above.
MAINTENANCE AND ADJUSTMENTS
ANTENNA TRIMMER ADJUSTMENT
An antenna trimmer adjusment screw is provided for
matching of the antenna coil in the receiver to the car antenna. This adjustment must always be made after
installation of a receiver or an antenna, or after re-
pair to these units. This adjustment should also be
performed whenever radio reception is unsatisfac-
tory.
1. Position antenna to a height of 31 inches.
2. Tune receiver
tb a weak station at or near 1400
KHz that can barely be heard
with volume turned
fully up.
3. Insert a small-bladed screwdriver in antenna trim-
Figure 9C-1 Location of Access Trim Plug
Figure
9C-2 Removing Hex Head Screw

RADIO - OPEL 1900 - MANTA9c- 109
RADIO
OPEL 1900
- MANTA
CONTENTS
Subject
DESCRIPTION AND OPERATION: (Not Applicable)
DIAGNOSIS:
RadioTroubleDiagnosis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .MAINTENANCE AND ADJUSTMENTS:
Antenna Trimmer Adjustment
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .MAJOR REPAIR:
Removal&InstallationRadio. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal81InstallationAntenna. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SPECIFICATIONS:Page No.
9c-109
9c-110
9c-111
9c-111
DIAGNOSIS
RADIO TROUBLE DIAGNOSISBecause radio problems are most often repaired at
United Delco authorized warranty repair stations,
the tendency for many dealer servicemen is to
remove the set when a problem is reported, without
any preliminary diagnosis. This results in a large
number of radios showing up as “NO TROUBLE
FOUND” units when received by the warranty re-
pair stations. This indicates that the trouble can
often time be corrected without removal of the radio.
The inconvenience to an owner of driving without a
radio while his set is being serviced at a warranty
station can frequently be avoided if the following
quick checks are used to eliminate external radio
system Problems before removing the radio for re-
pair.
Always determine from the owner the exact nature
of the radio problem as an aid to diagnosis. Knowing
whether! the condition is intermittent or constant,whether::it occurs with engine off or running, with
car stationary or moving, will help to pinpoint theproblem: Never turn on radio with speaker discon-
nected.
Radio Is Inoperative
1. Turn on the radio. The dial should light and a
thump should be heard from the speaker.a. If a thump is heard, go to
Step No. 2 for antenna
check.b. If no thump is heard, check the fuse.
(1) If fuse is bad, replace and try radio again. Race
engine and, if fuse blows again, remove the radio and
speaker assembly for repair by a trained radio techni-
cian.
(2) If fuse is good, check to see that the speaker to
receiver interconnecting cable is connected securely.
If there is still no thump when the radio is turned on,
remove the receiver and speak+ for repair.
2. Check the antenna by substituting with one held
out the car window.
a. If radio is still dead with’substitute antenna,
remove the receiver and speaker for repair.
b. If radio operates near normal with substitute an-
tenna, some part of the car antenna or lead-in is at
fault.
Radio Reception Is Weak1. Check to see if antenna
tri$mer is peaked.
a. Position antenna at a height,of 31 inches.
b. Tune radio to weak station at or near 1400 KHz
on the dial, and turn volume control to maximum.

9C-110 197j 6PEi SERVICE MANUAL
c. Adjust trimmei screw for maximum volume,
d. If antenna trir&ner does not have a definite peak,
check for defective ant&ma by substitution.
2. Check that the speaker connection is plugged in
securely.3. If the radio is still weak, remove the receiver and
speaker assembly for repair.
Radio Is Noisy1. Radio is noisy all the time:
a. Check for defective antenna by striking antenna
with hand. If static is heard while tapping, replace
antenna.
b. If antenna is not defective, remove receiver and
speaker for ripair.
2. Radio is noisy only when jarred:
a. Check antenna as in Step No. 1 above.
b. Check speaker connection. If speaker connection
is not at fault, remove receiver and speaker for re-
pair.
3. Radio is noisy when engine is running:
a. Check noise suppressor by substituting on genera-
tor with known good one.
b. Check to see that antenna is mounted securely,
grounding the antenna base to the fender. The an-
tenna lead-in wire is shielded and the shield should
have good ground corinection at the receiver and the
antenna base.
c. Check for other car wiring passing too close to
radio receiver case.
d. If engine noise is still present, remove receiver and
speaker for repair.
4. Radio is noisy when car equipment is operated,
such as directional lights or brake lights:
Check for defective antenna lead-in wire or loose
antenna mounting, as in Step No. 3b above.
5. Radio is noisy only on dry days when car is mov-
ing:
Wheel and tire static will occur only during dry
weather. To check to see if noise is wheel static or tire
static, drive car until noise is noticed. Touch the
brake. If noise disappears, it is wheel static. If noise
persists, it is tire static. Static may be eliminated in
two ways:a. Wheel static may be eliminated by installation of
static collectors in the front wheels. It is important
to make sure the button on the end of the spiral
collector rides evenly in the spindle. Grease and dirt
can cause poor contact between static collector and
the cap, which would result in wheel static, even with
the collectors installed.
b. Tire static is eliminated by injecting graphite tire
static powder in all
five (5) tires. Either a special gun
or a plastic squeeze bottle can be used to insert pow-
der.MAINTENANCE AND ADJUSTMENTS
ANTENNA TRIMMER ADJUSTMENTAn antenna trimmer adjustment screw is provided
for matching of the antenna coil in the receiver to the
car antenna. This adjustment must always be made
after installation of a receiver or an antenna, or after
repair to these units. This adjustment should also be
performed whenever radio reception is unsatisfac-
tory.1. Position antenna to a height of 31 inches.
2. Tune receiver to a weak station at or near 1400
KHz that can barely be heard with volume turned
fully up.
3. Insert a small-bladed screwdriver in antenna trim-
mer screw and rotate screw until maximum volume
is achieved.
Figure 9C-15 Radio Control Knobs