Page 311
5. Mount the slip ring cap and at the same time insert
the brush holder and contact point through the opening. Tighten the screws to a torque of 2.2 ft.lb. (3 Nm,
0.3 kpm).
6. Fit the washers and nuts on the diode holders. Check
the insulation.
7. Mount the brush holder and contact point.
TESTING, MAKE BOSCH AND SEV
General
Note the following before testing the alternator or its
component parts:
Only direct current with a maximum voltage of 40 V
may be used to test the rectifiers.
A 40V/40W AC glow lamp should be used for insulation
and short circuit tests on stator windings and rotor windings. (Do not use a mains voltage of 110 or 2;20 V, since
this might damage the rectifiers.)
The battery cable must not be disconnec~ed while the engine is running for the purpose of measuring the charging
current.
If it is necessary to solder or unsolder diode connections,
the diode connecting wire must be held in a pair of flat
pliers to conduct away excess heat, on account of the
heat sensitivity of the semiconductors. (Solder and unsolder the connections quickly with a hot soldering iron.)
Avoid mechanical strain at the point where the connecting wires issue from the heat sink assembly; the wire must
not be bent or subjected to load at the point of attachment.
During repairs to the alternator, whether in the car or on
a test bench, the battery must be disconnected.
Rapid check of alternator and charging regulator (applies
only to earlier design with separate charging regulator)
If the charge indicator light does not go out, the first
thing to do is to check that the alternator belt is not slipping and/or that the cable connections have not loosened.
If the lamp still glows after checking in this way, the cause
can be determined in the following manner:
Remove the connector from the charging regulator.
Connect a cable between the red cable's terminal D+ and
the yellow cable's terminal OF.
Start the engine and let it run at max. 2,000 rev/min
while watching the charge indicator light.
WARNING
Do not run the engine at a higher speed than 2,000
rev/min, as there is a risk of damage to the power
consumers being caused by overvoltage.
If the indicator light goes out immediately, the charging
regulator is defective and must be renewed.
If the indicator light flashes or lights continuously, the
alternator must be overhauled.
Measuring the charging capacity
The charging voltage and charging current can be measured in the car or on the test bench.
Measure the voltage using a voltmeter connected between
terminal B+ and the alternator ground.
Measure the current using an ammeter connected in series
with the wire from terminal B+ on the alternator. See the
test values on page 321-15.
Testing the alternator on a test bench
When on the test bench, the alternator must be driven by
its belt pulley only.
Connecting wires must be fitted with cable shoes or pin
connectors. Improvised connectors must not be used on
the battery either.
During testing a 12 volt battery must be coupled in parallel with the alternator. The battery serves as a buffer to
damp out the peak voltages that occur when the load is
switched on and off. If these peaks exceed the permitted
maximum voltage, the rectifier effect of the diodes will
be lost. The voltage limit for silicon diodes is about 100 V.
Mounting the alternator
The alternator can be tested in most types of generator
test bench. In some cases it may be necessary to provide
suitable extra mounting and drive arrangements.
CAUTION
When mounted for testing the alternator must be
secured by screws in the normal manner and not
clamped in place or secured by other means.
TERMINALS
DF AND D+ CONNECTED
5MB
321-13
Page 312
Testing with the voltage regulator
Mount the alternator in the test bench and connect it to
the voltage regulator. Do not misconnect the terminals!
Connect the excitation ammeter to terminal DF on the
alternator. Connect the battery and indicator lamp. Connect the voltmeter to terminal B+. For bias, increase the
speed from zero until an alternator voltage of about 14 V
is obtained, then reduce speed again.
Short circuit to ground
Test the insulation of the exciter winding and the slip
rings for a short circuit to ground.
Test equipments: 40V /40W AC glow lamp.
Magnetizati':)n
Unlike a DC generator, the alternator does not demagnetize spontaneously after a long period of disuse. A 12 V
indicator lamp with a power of at least 1.2-2 W must
therefore be connected between terminals D+ and B+
(see wiring diagram). Bias current is then supplied to the
exciter winding through the indicator light, alternator
terminal D+, regulator terminal D+, the closed regulator
contacts and terminal DF. It is important in this connection that the lamp wattage is at least as high as that stated
above. Self-excitation begins as soon· as the alternator voltage opens the exciter diodes, which occurs at 1-2 V. The
voltage then rises rapidly and the potential difference
across the indicator lamp gradually diminishes. The lamp
remains lit until battery voltage has been attained.
Testing the components
A. Rotor
Short circuit in the winding
Measure the resistance in the winding from slip ring to
slip ring using an ohmmeter.
The resistance should be:
Bosch alternator
4.0-4.4 ohm
SEV alternator
4 ± 0.4 mm
MEASURING THE RESISTANCE OF THE ROTOR WINDING
321-14
CHECKING THE INSULATION
AND THE·SLIP RINGS
OF THE EXCITER WINDING
Slip rings
Check that the surface of the slip rings is not greasy, dirty
or scratched. Clean using trichloroethylene. Avoid polishing the surface of the slip rings. A ring which is too highly
polished may impair the electrical contact of the brushes.
Page 313
B. Stator
Short circuit in the windings (rectifiers unsoldered)
The test for a short circuit in the stator windings can be
made by probing with a winding tester. This test can only
be made when the alternator is disassembled. A further
possibility is to measure the joint resistance in two phases.
Three measurements will reveal any deviation in the resistance of the stator winding. If the phases are marked
U, V and W, measure U-V, U-W and V-W. In each case
the reading should be (at 68°F/20°C):
Bosch 55A
0.14 ohm± 10 %
Bosch 65A
0.10 ohm± 10 %
SEV 55A (earlier design) 0.18 ohm± 10 %
S4024
TEST OF STATOR WINDING
C. Rectifiers
S6835
SEV 55A (later design)
Testing the rectifiers
Use only a testing lamp of not more than 40 V direct current or an ohmmeter. To test the conducting and nonconducting directions of the silicon rectifiers, the phase
terminals must first be disconnected, as it is otherwise
impossible to tell which diode is faulty. The positive diodes between terminal B+ and phase conduct from the
terminal to the casing but not from the casing to the terminal. The negative diodes connected between phase and
B- (inverse polarity) conduct from the casing to the terminal but not from the terminal to the casing (see illustration). To test this, connect the testing lamp in series with
the diode under test. The lamp should light up when B+
is connected to the anode of a diode with normal polarity.
The lamp should not light up when B+ is applied to the
casing. If the diode has inverse polarity, the lamp will light
up when B+ is connected to the terminal (cathode) but
not when the direction of current flow is reversed. A faulty
diode that fails to pass current in the conducting direction
has been overheated by excessive current intensity. A diode that passes current in both directions has probably
been subjected to excessive voltage.
0.13oJ,m±10%
54023
MEASUREMENT
OF RESISTANCE ACROSS TWO PHASES
(V-W)
Short circuit to ground (rectifiers unsoldered)
The test should be made with a 40V /40W AC glow lamp.
Connect the glow lamp between the iron core of the stator and each of the disconnected stator cables.
SA.Ml
321-15
Page 314
Terminal
(cathode)
Terminal
(anode)
Conducting
direction
Non-conducting
direction
Conducting
direction
*
l
Casing
+Diode
Testing rectifiers with an ohmmeter
The rectifiers can also be tested with an ohmmeter. In a
properly working diode, resistance is low in the conducting direction (e.g. a few ohms) but much greater in the
non-conducting direction (e.g. several kiloohms).
-Diode
Casing
D. Checking the brush unit assembly and connections
(brush unit assembly detached or rotor removed)
1. Check the movement of the brushes in the assembly.
2. Check the wear of the brushes. Compare with wear
limits on page 321-15.
3. Check that the brushes are completely insulated from
each other. Connect the testing instrument between
two brushes.
4. Check that the contact between each of the brushes
and the "-" and "D F" terminals is good.
E. Insulation test on assembled alternator
After disassembling and assembling the alternator, check
the insulation between the B+ terminal and ground with
an insulation tester.
CHECKING THE DIODES
321-16
l
1
l
Page 315
TEST VALUES AND WEAR LIMITS
Ratio engine belt pulley-alternator,
Maximum permissible wear of the brushes
Earlier version: The minimum length of the brushes should
be 0.35 in. (9 mm). However, during overhaul, the brushes
should be replaced if the length is below 0.55 in. (14 mm).
Later version: With the brush unit assembly removed, the
brushes should protrude by at least 0.20 in (5 mm) through
the opening in the brush unit assembly.
see Group 0.
Boschalternator
Testing at 2/3 maximum current·
Connect the battery and load the alternator. Adjust the
alternator speed to exactly 2,000 rev/min. The alternator
must then deliver two-thirds of the maximum current=
36A.
SEV alternator
At 3,000 rev/min., the alternator should generate
14V/48A.
At 5,000 rev/min., the alternator should generate
14V/55A.
Maximum permissible wear of the brushes:
The brushes should project more than 0.16" (4 mm) from
the brush unit assembly when the latter is removed ..
Checking speed for maximum output
Connect the battery. Load the alternator and run it until
warm. Increase the speed. The maximum output 55A or
65A respectively at 14V should be obtained within the
speed range 2,700-3,700 rev/min. (alternator speed).
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AMPERAGE OUTPUT IN THE ALTERNATOR,
MAKE SEV
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SA1B
321-17
Page 316
TROUBLE SHOOTING
Alternator not charging
The cause may be
a. Slack drive belt
b. Break in charging circuit and return circuit to ground
c. Defective electric brushes
d. Shorted diodes
e. Break in exciter circuit
f. Faulty regulator
g. Broken rotor winding
h. Grounded stator
i. Exciter diode unit ground connection broken or shorted
e. Broken or shorted rectifier diode
f. Partly shorted rotor
g. Stator ground connection broken or partly shorted
Abnormally high amperage
The cause may be
a. Faulty regulator
b. Bad contact between regulata_rand alternator
Noise in alternator
Low or irregular amperage
The cause may be
a. Slack drive belt
b. Irregular breaking in the charging circuit
c. Worn electric brushes
d. Faulty regulator
321-18
The cause may be
a. Badly worn drive belt
b. Pulley loose or out of true
c. Crankshaft and alternator pulleys out of alignment
d. Worn or defective bearings
e. A shorted rectifier diode
f. Loose alternator retaining screws
l
Page 317
STARTER
GENERAL
The starter spins the engine flywheel by a starter pinion
and a gear ring. The pinion slides on the rotor shaft of
the starter and is brought into engagement with the gear
ring by a solenoid which thereupon trips the switch that
supplies current to the starter. As soon as the engine fires,
the gear ring on the flywheel starts to drive the pinion.
When this happens, the pinion is released from the driver
shaft by a freewheel arrangement but remains in engagement with the ring gear as long as the solenoid is energized by the ignition key. It is disengaged by a return
spring when current to the solenoid is cut off.
DISASSEMBLING'
(See exploded view on the next page.)
REMOVAL
1.
2.
3.
4.
1. Disconnect_.the battery
2. Disconnect the pre-heater hose
3. Remove the clutch cover (torque converter)
4. Remove the starter motor rear mounting and the radiation shield
5.
6.
7.
8.
9.
10.
11.
,
12.
13.
14.
Disconnect the solenoid feeder cable.
Remove the solenoid retaining screws.
Unhook and remove the solenoid.
Undo the two retaining screws from the capsule
bracket.
Remove the capsule bracket, U-washer, spacers and
rubber gasket (pos. 5-8).
Undo the screws from the commutator bearing
housing (1).
Remove the commutator bearing housing (10).
Lift the brush springs off their retainers with a
wire hook and remove the brushes.
Remove the brush plate ( 11).
Pull the starter assembly off the drive and bracket
assembly.
Undo the engaging lever arm locating screw.
Remove the rubber and steel washers from the drive
and bracket housing (15-16).
Remove the rotor and engaging lever arm.
Press the stop ring towards the cog with a piece of
tubing.
5. Disconnect the starter motor wires
6. Remove the starter motor front mounting bolts
7. Extract the starter motor until it clears the recess and
then lift it out of the engine compartment
Installation is in the reverse order.
REMOVAL, TURBO
1. Remove the battery and battery shelf
2. Remove the turbo suction pipe
3. Remove the oil return pipe between the turbo charger
and the engine block.
4. Remove the pre-heater hose and the clutch cover
5. Remove the starter motor front mounting bolts
6. Disconnect the starter motor wires
7. Remove the starter motor rear mounting and radiation
shield
8. Extract the starter motor until it clears the recess and
then lift it out of the engine compartment.
S 1338
PUSHING DOWN THE STOP RING
15.
Installation is in the reverse order
5'\ftll
.L
Remove the lock ring with lock ring pliers (see illustration). Remove the pinion.
331-1
Page 318
ASSEMBLING
1.
2.
3.
4.
Lubricate the spiral splines and the drive cog engaging ring with silicone grease.
Mount the pinion, stop ring and lock ring on the
rotor shaft.
Use pliers to seat the lock ring in i~s groove in the
rotor shaft.
Push up the stop ring using a press or claw puller .
. S 1340
REMOVING.THE
16.
17..
LOCK RING
Inspect the spiral splines on the rotor shaft for
burrs. If there are any, file them off.
Check the gear ring, starter drive cog and the bushings.
PUSHING UP THE STOP RING
NOTE
Check all components and exchange or repair any
that are damaged. Soak the bearing bushings in hot
oil before reassembling.
5.
6.
7.
Fit the engaging lever arm to the cog engaging ring
and insert the assembly, together with the rotor,
into the drive housing.
Secure the engaging lever arm with its locating
screw.
Place the washers in the drive housing, first the
steel washer and then the rubber washer. The lips
must be t1.1rnedtowards the rotor.
2
1
3
0
4
l
I s 4161
STARTER, DISASSEMBLED
1. Screws, bearing housing
2. Solenoid
3. Drive housing
4. Bushing, drive side
5. Capsule bracket
6. U-washer
7. Shim
8. Rubber gasket
9. Bushing, commutator side
10. Commutator bearing housing
11. Brush plate
12. Field winding
13. Starter housing
14. Rotor
SAAB
331-2
I
I
I
15. Rubber washer
16. Steel washer
17. Engaging lever arm
18. Pinion
19. Bushing, pinion
20. Stop ring
21. Lock ring
Page 319
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
Fit the starter housing with the notches above the
guide pin and the lip of the rubber washer.
Fit the brush plate. Lift the brush springs with a
wire hook and insert the brushes.
Mount the commutator bearing housing with the
notches above the feed cable's rubber insulation.
Fit the rubber gasket, shims and U-washer.
Locate the capsule bracket and secure it with the
two screws.
Insert and tigt,ten the bearing housing screws.
Check the axial play of the shaft 0.002-0.012"
(0.05-0.30 mm) and correct with shims if necessary.
Hook the solenoid to the engaging lever arm and
secure with the two screws.
Connect the feeder cable.
Test the starter (see Group O for specifications and
test values).
SOLENOID
Installation
(Starter removed from car)
1
Removing
Wire the new brushes to the brush plate and field winding by soldering.
a. Skrapa ren anden paanslutningsledningen saatt
den blir helt blank.
1. Disconnect the feeder cable.
2. Remove both retaining screws and remove the solenoid.
Refitting
1. Hook the solenoid to the engaging lever arm and secure it with the two screws.
2. Connect the feeder cable.
3. Test the starter (se~ Group 0).
BRUSHES
(Starter removed from car)
Removing
$7223
1. Remove the two screws from the capsule bracket.
2. Remove the capsule bracket, U-washer, shims and rubber gasket (pos. 5-8).
3. Remove the screws from the commutator bearing housing ( 1 ).
4. Remove the commutator bearing housing ( 10).
5. Lift the brush springs from the holders with a wire
hook and take out the brushes.
6. Remove the brush plate.
7. Use a hammer to break up the worn bushes.
SAAB
331-3
Page 320
b. Stick in ledningen i halet paden nya el-borsten och
dela isar ledningstradarna i fordjupningen i el-borsten.
d. Fila bort ev utskjutande tennrester och tvatta bort
eventuella rester av lodpastan med sprit.
c. Lod fast el-borsten med lodkolv och tenn.
Hall fast ledningen med en tang for att forhindra
att tenn flyter ut i ledningen.
I s 4762
BRUSH PLATE AND FIELD WINDING
2. Fit the brush plate in position. Lift the springs with a
wire hook and insert the brushes.
3. Mount the commutator bearing housing with the
notches above the feed cables rubber insulation.
4. Fit the rubber gasket, shims and U-washer.
5. Locate the capsule bracket and secure it with the two
screws.
6. Insert and tighten the bearing housing screws.
7. Check the operation of the starter (see Group 0).
S 7225
331-4
SAAB