1973 OPEL GT-R light

BATTERY AND CABLES - ALL MODELSlA- 9
plus 61 terminal of the voltage regulator and protects
the circuit to the generator telltale light.
BATTERY RECHARGING
There are two separate methods of recharging batter-
ies which giffer basically in the rate of charge. In the
slow-charge method, the battery is supplied a rela-
tively small amount of current for an extended
period of time. In the quick-charge method, the bat-
tery is supplied with a high current for a short period
of time.
Slow-Charging
Slow charking is the best and only method of com-
pletely ch+rging a battery. The slow-charge method,
properly applied, may be safely used under all possi-
ble conditions of the battery, provided electrolyte is at proper
wl in all cells. The battery may be fully
charged by this method, unless the battery is not
capable of taking a full charge. The normal slow
charging rate for the
12.volt battery is 5 amperes.
Full ch&e of battery is indicated when all cell spe-
cific gravities do not increase when checked at three
intervals
of one hour and all cells are gassing freely.
Due to the low rate during slow charging, plenty of
time must ,be allowed. Charge periods of 24 hours or
more are often required.
Quick-Charging
Since time!is often of most importance to the battery
owner, quick-charging must sometimes be used to
partially charge the battery so that the engine will
start and the owner can be on his way.
Charge at:50 amperes for 20 minutes (50 times 20
equals
100Q ampere minutes). If charger will not give
this rate, charge for an equal number of ampere mi-
nutes at the best rate available. Too high a current
during quick-charging will damage battery plates.
A battery cannot be brought up to a fully charged
condition
by the quick-charge method. The battery
can be substantially recharged or boosted, but in
order to bring the battery to a fully charged condi-
tion, the charging cycle must be finished by charging
at a low
oi normal rate. Some quick-chargers have
a
provisioA for finishing the charging cycle at a low
rate so
tha’t the battery can be brought up to a fully
charged condition.
Used
with:care, and employing all safeguards prov-
ided by the manufacturer, a quick-charger will not
damage a battery
which is in good condition.
BATTERY REMOVAL AND INSTALLATION
Removal
1. Disconnect battery cables (remove negative cable
first to prevent possible shorting).
2. Remove battery hold down
l&acket.
3. Remove battery.
Installation
‘1. Place battery back in hold down position.
2. Tighten hold down bracket bolts.
3. Connect battery cables (connect positive cable first
to prevent possible shorting).
FUSIBLE LINK REMOVAL AND INSTALLATION
Replace a burned out fusible link as follows:
1. Disconnect battery.
2. Disconnect connector eye on end of fusible link.
3. Cut off other end of burned out link, along with
solder joint.
4. Strip insulation from end of new fusible link and
from end of wiring harness so that each will slide into
soldering sleeve.
5. Crimp new link in soldering sleeve and solder
carefully.
6. Cover new connection tightly with electrical tape.
I. Install new link connector eye on other end of
fusible link.
A burned out fusible link connected to the starter
solenoid would be indicated by:
1. All electrical accessories dead.
2. Starter dead - will not even click. Even with a
nearly dead battery, the starter solenoid will
gener-
ally engage; therefore, no click means no solenoid
action, possibly due to a burned out fusible link.
SPECIFICATIONS
BATTERY SPECIFICATIONS
Delco-General 12 volt-44 amp hour storage battery
is installed as original equipment. Replace with a
Delco Energizer
Y55.

19- 12 1973 OPEL SERVICE MANUAL :ConditionPosiible CauseCorrection4. Voltage drop.1. Check wiring and wiring
connections.
5. Overrun&g clutch slips.1. Replace overrunning clutch.
The cranking motor keeps
on rotating after ignition
switch is off.1. Ignition
{witch does not
cut off or solenoid switch
sticks.
1, Immediately disconnect cranking
motor cable from battery. Inspect
and/or replace or repair ignition and
solenoid switches as required.
The drive pinion does notdemesh after engine has
been cranked.1. Drive pinion or ring gear
1. Clean components as specified.
teeth clogged or flattened.Replace as required.
Return spring slack or broken.MAlNTEilANCE AND ADJUSTMENT
/
STARTING SYSTEM CHECKS
Voltage Loss ChecksWhen the starter cranks too slowly, check the bat-
tery state of charge and all electrical connections
between the battery and starter.
1. Turn on headlights and
opera’te starter. If head-
lights dim considerably when starter is engaged, the
battery may be discharged or be defective. Check the
battery.
2. If the headlights stay bright but the starter d&s
not turn over, the starter cables may be faulty or the
starter defective.
(a) Test battery voltage while cranking engine
1(9volts minimum).
(b) Check voltage from starter tkrminal of solenoid
to starter frame while cranking engine.
3. The difference in readings taken in Operations 2a
and 2b above represents the
volt& drop through the
cables and solenoid switch. Voltdge drop should
Gotexceed
.5 volt.
4. Locate excessive resistance as follows:
(a) Turn voltmeter to scale above 12 volts and con-
nect voltmeter leads
across connection or switch: to
be checked.
(b) With starter switch closed, turn voltmeter switch
to lowest scale and take reading as quickly as possi-
ble, then turn switch back to higher scale and stop
cranking engine.(c) Voltmeter must not read more than
.2 volt across
any
c:onnection. If voltmeter reads more than .2 volt,
the
d~efect must be corrected.
Starter Current Draw - Lock Test1. Make sure battery is fully charged and in good
condition.
2. Connect a volt ampere starter tester according to
manufacturer’s instructions.
3. Pull parking brake on securely, shift transmission
into 4th (direct) gear and actuate starter. (Starter will
not
t,urn engine because engine is locked through
transmission.)
4. While starter is actuated, read voltage and current.
Refer to Specification Chart.
(a) Voltage low
_ poor battery or a voltage loss in the
starter circuit.
(b) Current high
- short circuit in starter. Overhaul
starter.
(c) Current low
- commutator dirty, brushes worn,
solenoid switch contacts defective or open circuit in
starter. Overhaul starter.
Starter Current Draw. On Car1. Bring engine to normal operating temperature.
2. Stop engine and disconnect coil wire from dis-
tributor.
3. Ground coil wire to prevent excessive coil voltage
build up.

lB- 14 1973 OPEL SERVICE MANUAL !
6. Remove shift lever shaft and: lift armature aid
shift lever assembly.
7. Drive back retaining ring on armature shaft. See
Figure
lB-5.
8. Take the lock ring, retaining ring, and
over&-
ning clutch and pinion off armature shaft. Cheqk
groove in shaft for burrs and remove with a soft tile.
Cleaning and Inspecting Parts
1. Clean and check all parts. Replace defective parts.
2. Turn down worn or burnt
cominutator on a good
precision lathe. Use a spindle
speed between 2,000
and 3,000 RPM. See Figure
lB-6. When turning
down commutator, adjust cutting depth of tool
so
that no more pits exist after this:operation. Do not
remove any more material than necessary, however,
because if commutator diameter
is less than 1 15/32
inches, armature must be replaced.
30166
Figure 1B-6 Turning Down Commutator
3. Undercut mica approximately ,020 below com-
mutator surface. Finish and thoroughly clean
corn-
mutator.
I
4. Check armature for short circuit on a
growler.
5. With a test lamp, check armature for ground.
Test
lamp must not light up. See Figure
IB-7.
Figure 1B-7 Testing Armature for Grounds
j
6. Check armature for an open circuit on a growler.
Considerable variation in readings between in-
dividual commutator bars would indicate an open
circuit.
7. Visually check
field coils. Replace burnt or
scorched
field coils.
8. With a test lamp, check
field coils for ground. See
Figure
IB-8. Test lamp must not light up. Replzice
grounded field coil.
Figure lB-8 Checking Field Coils for Ground
Replacing Field Coils
1. Mark locations of pole shoes to avoid incorrect
installation.
Figure 1B-9 Removing Pole Shoes

STARTING SYSTEMlS- 15
2. Unscrew the four (4) pole shoe attaching bolts and
take
field coils out of field frame. See Figure lB-9.
3. To ensure proper installation of the pole shoes,
align shoes exactly parallel with the armature shaft
prior to tightening attaching bolts.
Checking
a’nd Replacing Brushes
1. Check
b&h positive brush holders for ground. See
Figure
lB-,lO. Test lamp must not light up.
Figure 1g-10 Checking Positive Brush Holder forGrounds
2. Check brushes. Replace brushes, if worn down to
.28 inches or less. Always replace all four (4)
brushes.
3. To replace positive brushes, cut off wires at the
connecting strap of the field coil. Clean soldered joint
and solder stranded wire of new brushes. Hold wire
with
flatnose pliers so that no tin enters wire strands.
4. On replacement of the negative brushes, the com-
plete brush holder with the welded brush has to be
replaced. 5. Shear off rivet head with a chisel and drive rivet
out. See Figure
lB-11.
6. A tool to replace the negative brush holder and
rivet can be made up out of
l/4 inch steel. See Figure
Figure 18.12 Negative Brush Holder Installation Tool
7. Place new brush holder and new rivet on installa-
tion tool and insert rivet into bore of
field frame. See
Figure
lB-13.
Figure 1B-11 Removing Rivet Figure 18-13
Brush Holder and Rivet Installed on Tool

1 C- 18 1973 OPEL SERVICE MANUAL
IGNITIPN SYSTEM
CbNTENTS
Subject
DESCRIPTION AND OPERATION: Ignition System ..................................................................
Ignition
Switc,h....................................................................
Ignition Coil
..........................................................................\
Distributor
............................I...............................................
DIAGNOSIS: (Not Available)
MAINTENANCE AND ADJUSTMENTS: Contact PointReplacement ............................................
Dwell Angle Adjustment :
................................................
Ignition Timing Adjustment ..........................................
Ignition Wire Inspection :
..................................................
Check Ignition Output ......................................................
Check Distributor
..............................................................
Check Spark Plugs
............................................................
MAJOR REPAIR: Distributor Removal ..........................................................
Disassembly ........................
I...............................................
Reassembly
..........................I...............................................
Distributor Installation
....................................................
SPECIFICATIONS: /
Ignition
Coil ..........................................................................
Distributor
....‘........................i...............................................
Spark Plugs ........................................................................\
..
DESCRIPTION AND OPERATION
INGITION SYSTEM
The ignition system basically consists of an ignitipn
switch, ignition coil, distributor, battery and related
wiring. The ignition switch is located in the steering
column, the ignition coil is located left front inner fender
skirt and the distributor is located at the left
front of the engine.
IGNITION SWITCH
The combined ignition switch and steering lock ian
be switched to any one of the below listed positions.
Insert key with notch pointing upward.
Page No.
lC-18
lC-18
lC-19
lC-19
1 c-20
1 c-20
1 c-20
lC-21 r
lC-21
1 c-22
1 c-22
1 r-23
1 C-23
1 c-24
1 C-25
1 C-26
1 C-26
1 C-26
(Fully counterclockwise) Lock position. Ignition
locked, steering locked, only with key removed.
Electrical circuits disconnected except to main light-
ing switch and dome lamp. The
key can be removed.
0- (First position clockwise from lock) Garage posi-
tion. ‘The key and lock assembly must be pushed “in”
to reach this position from lock. The steering is un-
locked and the ignition is off. The electrical circuits
are the same as in lock position. The key cannot be withdrawn.
l- [Chposition.) All electrical circuits controlled by
ignition switch are completed through the switch.
The key cannot
be removed while switch is in drive
position.

I
ilC- 201973 OPEL SERVICE MANUAL
There is also a plastic hood slipped over the distrivu-tar cap with an outlet for the ignition cables as an
added protection against moisture from the outside.
See Figure lC-2.
Figure lC-2 Ignition Distributor With Hood Installed
MAINTENANCE AND ADJUSTMENTS
CONTACT POINT REPLACEMENT
Removing Contact Points1. Remove contact support lock
,screw and remqve
contact point support. If condenser is to be replaced,
it will be necessary to replace condenser and
1eads;asan assembly.
Installing Contact Points1. Lightly lubricate distributor cam with high tein-perature cam and ball bearing lubricant. Excessive
lubricant will throw off into contact points.
:
,
2. Position support on breaker plate and install lock
screw leaving slightly loose for later adjustment..
3. Plug breaker arm wire in.
4. Adjust breaker point gap to ,016”.
/
DWELL ANGLE ADJUSTMENT
1. Connect dwell meter.
2. Remove distributor cap. Remove rotor. Loosen
breaker point set screw approximately
l/8 turn.
3. Insert screwdriver in notch of stationary breaker
point. Observe dwell meter while cranking engine.
Twist screwdriver as required to obtain a reading of
50 degrees plus or minus 3 degrees.4. Tighten breaker point set screw, then recheck
dwell.
5. Install rotor and cap.~Start engine and recheck
dwell. It is important that dwell be rechecked, as
instal~lation of rotor and cap will sometimes change
the dwell angle.
IGNITION TIMING ADJUSTMENT
Preliminary Timing (Engine Won’t Run)To time the ignition on any engine which will run,
use subparagraph b only. However, if the timing of
an engine is completely off, the following procedure
must first be used to get the engine to run.
1. With rocker arm cover removed, rotate crankshaft
in a clockwise direction until both valves for No. 1
cylinder are closed and the timing marks line-up.
(Valves are completely closed if rocker arms can be
“rocked” slightly.)
2. Install distributor in engine so that vacuum ad-
vance unit is in original position and notch in dis-
tributor rotor lines-up with notch in housing. See
Figure lC-3. If distributor does not seat in engine
block., turn distributor shaft so that rotor points
about 20 degrees clockwise from distributor timing
notch
(see Figure lC-18), then press lightly on dis-
tributor housing while cranking engine with starter.
After oil pump tang snaps into slot in distributor
shaft, start timing again from Step 1, leaving dis-
tributor installed.
Figure lC-3 Rotor Position for Filing No. 1 Cyliqder
3. Install distributor clamp and bolt, leaving bolt just
loose enough to permit movement of distributor. In-
stall distributor primary wire.L

IGNITION SYSTEMlC-214. Rota&distributor counterclockwise slightly until
contact pbints just start to open. This must be done
very carefully or engine will not start.
5. Install distributor cap. Make sure spark plug wires
are correctly installed in distributor cap, through clip
and on spark plugs.
Finish TimingIContact boint gap
(.016” at widest gap) or dwell 50
degrees plus or minus 3 degrees should always be
checked before adjusting ignition timing.
1. Connekt timing light to No. 1 spark plug.
2. Disconnect and plug vacuum advance unit and
retard u$it hoses.
3. Connect a tachometer from distributor side of coil
to
groun$l.4. Start dngine. Set idle speed to 900 RPM.
5. Rotate distributor as necessary to align timing
marks. T;ming mark is a steel ball embedded in the
flywheel and a pointer in a window in the right fly-
wheel housing. See Figure lC-4.:Figure lC-4 Ignition Timing Marks
6.
Tightq clamp bolt securely and recheck timing
mark ahgnment.
7. Reconnect vacuum hoses and adjust engine idle
speed
an: mixture.
IGNlTlOFj WIRE INSPECTION
1. The c$il and spark plug wires are of a specialresistance type. These secondary ignition wires
reduce television and radio interference.
2. Wipe ignition wires with a cloth moistened with
solvent and wipe dry. Bend wires to check for brittle,
cracked or swollen insulation. Defective insulation
will permit missing or cross-firing of spark plugs,
therefore any defective wires must be replaced.
3. If wire insulation is in good condition, clean any
terminals that are corroded and replace any termi-
nals that are broken or damaged. Terminals must tit
tight on spark plugs and in distributor cap.
4. Replace any hardened, cracked or loose cap nip-
ples or spark plug boots.
5. Check resistance of each wire from contact inside
distributor cap to spark plug or coil terminal. Re-
place any wire having over 10,000 ohms resistance
reading. See Figure lC-5.
Figure fC-5 Checking Ignition Wire Resistance
CHECK IGNITION OUTPUT
1. Disconnect secondary coil ivire so that engine will
not start. Connect a voltmeter from the battery side
of the coil primary to ground and check voltage
while engine is cranking. Reading should be 10 volts
or more. Low reading could be caused by a defective
battery, a discharged battery, high starter current
draw, a bad connection in the starter circuit or a bad
connection in the primary ignition circuit.
2. Connect an oscilloscope according to manufac-
turer’s instructions. Disconnect coil wire. Crank en-
gine and read coil output voltage. Reading should
exceed 20 KV (20,000 volts).

lC- 22 1973 OPEL SERVICE MANUAL j
3. Start engine and disconnect a wire from a spark
plug. Read output voltage of disconnected spark
plug circuit. Reading should exceed 20 KV
(20,poO
volts).I
CHECK DISTRIBUTOR
!1. Clean distributor cap and inspect it for cracks or
tracking. Inspect inner segments for erosion and
outer sockets for corrosion.
2. Clean and inspect ignition wires. Make sure resist-
ance of each wire is less than 10,000 ohms. Replace
any defective spark plug boots or distributor
capnipples. See paragraph lC-12.
3. Inspect breaker points and replace if necessary.
Adjust breaker point gap to
,016 inch with rubbing
block on peak of cam lobe or check dwell and adjust
if not 50 degrees plus or minus 3 degrees. 4. Check
dwell variation by reading dwell at idle and at 3000
RPM. Dwell must not vary more than 3 degrees.
Excessive variation means distributor shaft, cam or
breaker plate are worn or damaged--overhaul dis-
tributor and replace defective parts.
5. Check distributor condenser for a minimum series
resistance and insulation leakage. Check for a
capacity between
.15 and .20 microfarads.
6. Check total advance (centrifugal and vacuum) at
2500 engine RPM using a timing light having a dial
for reading advance.
(a) The timing marks are aligned with both the
vacuum advance and the vacuum retard hoses dis-
connected and plugged.
Engine idle should be 900 RPM.
(b) Reconnect vacuum hoses. Run engine at
3600RPM and adjust knob until timing marks are
aligned. Read advance on dial. Maximum centrifugal
advance should be between 28-32 degrees.
7. If total advance is out of specifications, check
centrifugal advance only, at
2500 RPM. Discon+ectand plug all vacuum hoses. Maximum vacuum ad-
vance should be l-5 degrees at 4.5-5.0 in. hg.
8. Replace centrifugal or vacuum advance parts as
required to bring distributor total advance within
specifications.
9. Check operation of vacuum retard unit (rear unit)
by first making sure timing marks are aligned with
vacuum hoses disconnected and at slow idle (700
RPM). Then connect vacuum hose to vacuum retard
unit (rear unit). Timing ball should move in a retard
direction (upward).
CHEICK SPARK PLUGS1. Remove spark plugs. If electrodes are badly worn,
discard plugs. If inner or outer porcelain is cracked
or broken, discard plugs.
2. Note color and general appearance of inner end of
spark plug. Brown to grayish
- tan deposits and slight
electrode wear indicate correct spark plug heat
range. Plugs having this appearance may be cleaned,
regapped, tested and reinstalled.
3. Clean spark plugs in a sand blast type cleaner.
Clean only enough to remove deposits, not enough to
wear away porcelain. If deposits are too hard to
remove or if porcelain is glazed, discard plugs.
4. After cleaning spark plugs, clean tiring surfaces of
electrodes with a line file.
5. Test cleaned spark plugs on a pressure tester by
comparing spark of the used plugs with that of a new
plug. Install tested plugs, using new gaskets.
6. If removed spark plugs have excessive carbon foul-
ing and if the car will be driven mostly at low speeds
in city driving, it is advisable to replace plugs with
a hotter plug, AC43FS.
7. If removed plugs show rapid electrode wear or
inner porcelain breakage at low mileage. Check for
a vacuum leak such as a poor manifold to head fit.
8.
Clap spark plugs carefully (new or cleaned) using
a
,030 round wire feeler gage.IC6
Figure lC-6 Distributor Installation