Page 84 of 625

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,INSTRUMENT PANELlH-63Figure l;H-15 Removing Instrument Cluster AssemblyFibure1 H-l 6 Disconnecting Radio Wires
14. Disdonnect antenna lead-in at right lower corner
of radio!
15. Pull’ cluster housing out and turn sideways to
remove
&~y instrument gauge or switches.
I
lnstallaiion
CAUTlOI$ Fasteners in subparagraph B are impor-
tant attaching parts in that they coo/d
affect the
perform>nce of vital components and systems, and-
/or
cou!d result in major repair expense.They must
be
repraced with one of the same part number, or
with an equivalent part if replacement becomes
necessa?y. Do not use a replacement part of lesser
quality
br substitute design. Torque values must be
used as
&ified during reassembly to assure proper
retention of these parts.
1. Plug antenna lead-in cable and power source to
radio. I
2. Put i&trument cluster in position and replace six
(6) screbs in cluster.3. Connect speedometer cable.
4. Raise steering column into position and install hex
head
bolt% Be sure to install ground wire. Tighten
hex head bolts to 14 lb.ft.
5. Tighten tear lock bolts until hex head of bolt is
torn off.
6. Connect ignition and directional signal wire set
plugs.
7. Install flasher unit.
8. Replace screws in right and left lower instrument
panel and replace both access covers.
9. Connect battery cable.
Removal of Combined Switch Assemblies. GT1. Remove instrument cluster.
2. Turn instrument cluster to the side to remove
switch assembly.
3. Remove switch by removing two retaining nuts.
See Figure lH-17.
4. Remove wiring from switch.
Figure 1 H-l 7 Removing Switches
Installation1. Plug wiring into switch.
2. Install switch on panel.
3. Install instrument cluster.
Page 88 of 625

I
GAUGES1 I- 67I
I Condition
Car
&s out of gas with
gauge indicating fuel in
tank. 1
I
I
I
I
IPossible Cause
1. Tank unit misadjusted
2. Defective voltage
stabilizer.Correction
1. Follow corrective action as
stated above (obtain empty
reading on dash)
1. See corrective action above.
Temperature gauge not1. Loose dash gauge1. See corrective action above.
Iattaching nut.
I
I
I2. Defective temperature1. Install 40 ohm resistor
Isending unitbetween temperature sneding
Iunit and ground (disconnect
I
from unit). If dash unit reads
I
full scale, replace temperature
Isending unit.
I
I
I3. Open wiring.1. Follow corrective action as
Istated above (connector socket
Iwith blue wire).Tempkrature gauge indicates
hot when engine temperature1. Incorrect temperature1. Check for correct sending unit
sending unit
normal.(white porcelain) replace if
incorrect.
2. i>efective temperaturesending unit.1. See corrective action above.
3. Dkfective voltage
stabilizer.
1. See Corrective action above.
GAS
GdUGE TROUBLE DIAGNOSIS - GT4. Disconnect the tank unit lead wire (light blue with
black tracer) from the tank unit.
An inoperative gas gauge reading can normally be
found to result from a poor grounding condition
within the circuit. Using the procedure as outlined
below may lead to the correction of the inoperative
reading without replacement of either the tank unit
or the
dph unit.5. Connect ihe stock tank unit; ground unit, and
operate manually.
6. If the dash unit shows a correct reading, then
replacement of the tank unit is required as the cor-
rection.
1. Makelcertain the gas tank (ground) strap is prop-
erly secured.A correct reading will be one which resembles the
movement of the manually-operated tank unit.
2. Make’certain the ground wire (brown in color) for
gasoline/ and temperature gauges is properly con-
nected tb the windshield wiper motor and is secured.
(This
gl?ound wire is also common for the heater
blower
etor.)7. If the dash unit does not show a correct reading,
then its replacement is necessary.
If the adove procedure does not produce a satisfac-
tory gaube reading, an attempt to isolate the defec-
tive
par<, i.e. tank or dash unit should be made.
3. Rem&e a tank unit from parts stock.MAJOR
AEPAIR
OPEL 1900. MANTA
Removing Voltage Stabilizer1. Remove instrument cluster housing assembly.
Page 93 of 625

1 J- 72 1973 OPEL SERVICE MANUAL
I
WIRING IDIAGRAMS
CONTENTS
Subject
1973 WIRING DIAGRAMS: Windshield Wiper and
Horn:- Opel 1900 -
Manta....................................I.............. ..............................
Windshield Wiper and Horn’- Rallye ..........................
Windshield Wiper
andHorn!-GT
..................................
Turn Signal and Hazard Flasher
-
Opel 1900 - Manta !
........................................................
Turn Signal and Hazard Flasher
- GT ..........................
Oil, Fuel,
Temp.: Tach, Stop and Brake
Warning Light
.GT........................................................
Blower Motor, Lighter and
Rackup Lights -
Qpel 1900.Manta ........................................................
Blower Motor and Lighter
.,GT....................................
Indicator Lights and Gauges
- Opel 1900 -
Manta ........................................................................\
........
Indicator Lights
andGauges.Rallye ..........................
Dome Light and Buzzer
- Opel 1900 - Manta..........
Dome Light, Buzzer and Clock - GT ............................
Headlamps
- Opel 1900 ’
....................................................
Headlamps
.Mantaj............................................................
Headlamps and Fog Lights
.Rallye ..............................
Headlamps, Parking, Tail and Instrument
PanelLighting.GT ........................................................
Left Parking and Tail Lights
- Opel 1900 -
Manta ..................................i.............................................
Right Parking and Tail Lights
- Opel 1900 -
Manta................. ..*............................................................
Starting, Ignition and Charging
-
Opel 1900.Manta..........i.............................................
Starting, Ignition and Charging
- GT ..........................
Instrument
Panel.GT ......................................................
A/C Generatorand Regulator
- All Models..............
Seat Belt Warning System (Manual Transmission)
-Opel1909-Manta ..........................
Seat Belt Warning System (Automatic Transmission)
.Opel 1900 - Manta..........................
Seat Belt Warning System (Manual Transmission)
- GT........................................................ Page No.
1 J-74
1 J-75
1 J-76
1 J-77
1 J-78
1 J-79
1 J-80
lJ-81
1 J-82
1 J-83
1 J-84
1 J-85
1 J-86
1 J-87
1 J-88
1 J-89
1 J-90
1 J-91
1 J-92
1 J-93
1 J-94
1 J-95
1 J-96
1 J-97
1 J-98
Page 94 of 625
I
/WIRING DIAGRAMS13-73ISeat Belt Warning System (Automatic
Page No.Transmission)
.GT.......................................................lJ-99HeatedRear Glass
.Opel1900.Manta...................15-100Heated Rear Glass
.GT..................................................*,lJ-101Opel 1900 Color Schematic.........................................
lJ-103Manta
ColorSchematic.................................................1 J-105GT
ColorSchematic
.........................................................1 J-107
Page 96 of 625
I
IWIRING DIAGRAMSlJ- 75
Figure lJ-2 Windshield Wiper and Horn
- Rallye
Page 98 of 625
!I
I
I
,WIRING DIAGRAMS1J. 77
I
IFigure 1 J-4 Turn Signal and Hazard Flasher . Opel 1900 - Manta
I
Page 100 of 625
I
WIRING DIAGRAMS15.79
IIFigure lJ-6
Oil. Fuel. Temp. Tach, Stop and Brake Warning Light. GT
I
Page 102 of 625
I
WIRING DIAGRAMSlJ- 81r
Figure 1 J-8 Blower and Lighter
- GT