check engine MITSUBISHI 3000GT 1992 2.G Owner's Guide

Downloaded from www.Manualslib.com manuals search engine 16-6ENGINE ELECTRICAL - Charging System
ON-VEHICLE SERVICEGENERATOR OUTPUT LINE VOLTAGE DROP TEST
+I I.=-@=
Voltmeter
This test determines whether the wiring from thegenerator
“B” terminal to the battery (+) terminal
(including the fusible link) is in a good condition
or not.(1) Always be sure to check the following before
the test.l Generator installation
l Generator drive belt tension (Refer to
GROUP 00 - Maintenance Service.)l Fusible link
l Abnormal noise from the generator while
the engine is running
(2) Turn the ignition switch to the OFF position.
(3) Disconnect the negative battery cable.
(4) Disconnect the generator output wire from the
generator
‘73” terminal and connect a DC testammeter with a range of 0
- 100 A in series
between the “B” terminal and the disconnected
output wire. (Connect the
(+) lead of the amme-ter to the
‘73” terminal, and then connect the
Battery
6EN0962(-) lead of the ammeter to the disconnected
output wire.)
NOTE
A clamp-type ammeter which enables measure-
ments to be taken without disconnecting thegenerator output wire is recommended. The
reason for this is if a vehicle in which the voltage
may have dropped due to an imperfect connec-tion at the generator
“B” terminal is being in-
spected, and the generator “B” terminal is loos-
ened when the test ammeter is connected, the
connection will be completed at this time andthe possibility of finding problems will be re-
duced.
(5) Connect a digital-type voltmeter between thegenerator
“B” terminal and the battery (+)
terminal. (Connect the (+) lead of the voltmeterto the “B” terminal, and then connect the
(-)
lead of the voltmeter to the battery (+) cable.)
’
1 TSB Revision

Downloaded from www.Manualslib.com manuals search engine ENGINE ELECTRICAL - Charging System16-7/
L
(6) Connect a tachometer. (For the procedure for
connecting the tachometer, refer to GROUP
- On-vehicle Service.)(7)
kkconnect the negative battery cable.
(8) Leave the hood open.
(9) Start the engine.
(lO)With the engine running at 2500 rpm, turn the
headlights and other lights on and off to adjust
the generator load so that the value displayed
on the ammeter is slightly above 30A.Limit value: Max. 0.3 V
NOTE
When the generator output is high and the value
displayed on the ammeter does not decreaseto
30A, set the value to 40A. Read the value
displayed on the voltmeter at this time.
In this case the limit value becomes max. 0.4V.
Adjust the engine speed by gradually decreas-
ing it until the value displayed on the ammeterOUTPUT CURRENT TEST
is 30A. Take a reading of the value displayed
on the voltmeter at this time.
(11) If the value displayed on the voltmeter is above
the limit value, there is probably a malfunction
in the generator output wire, so check the wiring
between the generator
“IS” terminal and the bat-tery
(+) terminal (including fusible link).
If a terminal is not sufficiently tight or if the har-
ness has become discolored due to overheating,
repair and then test again.(12)After the test, run the engine at idle.
(13)Turn off all lights and turn the ignition switch
to the OFF position.
(14)Disconnect the negative battery cable.
(15)Disconnect the ammeter, voltmeter and tachom-
eter.
(16)Connect the generator output wire to the genera-
tor “B” terminal.
(17)Connect the negative battery cable.
Charging indicatorGenerator
30A
Voltmeter
BatteryAmmeter
t
-Load
6EN0893
1 TSB Revision

Downloaded from www.Manualslib.com manuals search engine 16-8ENGINE ELECTRICAL - Charging System
This test determines whether the generator outputs
normal current.(1) Before the test, always be sure to check the
following.l Generator installation
l
Battery (Refer to GROUP 54 - Battery.)
NOTE
The battery to be used should be slightly dis-charged. The load in a fully-charged battery
will be insufficient and the test may not be able
to be carried out correctly.l Generator drive belt tension (Refer to
GROUP 11- On-vehicle Service.)l Fusible link
l Abnormal noise from the generator while
the engine is running(2) Turn the ignition switch to the OFF position.
(3) Disconnect the negative battery cable.
(4) Disconnect the generator output wire from the
generator
“B” terminal and connect a DC testammeter with a range of O-100 A in series
between the “B” terminal and the disconnected
output wire. (Connect the
(+) lead of the amme-ter to the
“B” terminal, and then connect the(-) lead of the ammeter to the disconnected
output wire.)
Caution
Never use clips but tighten bolts and nutsto connect the line.
Otherwise loose
connections (e.g. using clips) will lead to
a serious accident because of high current.
NOTE
A clamp-type ammeter which enables measure-
ments to be taken without disconnecting the
generator output wire is recommended.(5) Connect a voltmeter with a range of 0
- 20
V between the generator “B” terminal and the
ground. (Connect the
(+) lead of the voltmeterto the “B” terminal, and then connect the (-)
lead of the voltmeter to the ground.)
(6) Connect a tachometer. (For the procedure forconnecting the tachometer, refer to GROUP
11 - On-vehicle Service.)
(7) Connect the negative battery cable.
(8) Leave the hood open.(9) Check to be sure that the reading on the
voltmeter is equal to the battery voltage.
NOTE
If the voltage is 0 V, the cause is probably an
open circuit in the wire or fusible link between
the generator “B” terminal and the battery
(+)
terminal.
(1O)After turning the light switch on and turning on
the headlights, start the engine.
(1l)lmmediately after setting the headlights to high
beam and turning the heater blower switch to
the high revolution position, increase the enginespeed to 2,500
r/min and read the maximum
current output value displayed on the ammeter.
Limit value: 70% of nominal current output
NOTEl
For the nominal current output, refer to the
Generator Specifications.l
Because the current from the battery will
soon drop after the engine is started, the
above step should be carried out as quickly
as possible in order to obtain the maximum
current output value.l The current output value will depend on
the electrical load and the temperature of
the generator body.l
If the electrical load is small while testing,the specified level of current may not be
output even though the generator is normal.
In such cases, increase the electrical load
by leaving the headlights turned on for sometime to discharge the battery or by using
the lighting system in another vehicle, and
then test again.l
The specified level of current also may not
be output if the temperature of the generator
body or the ambient temperature is too high.
In such cases, cool the generator and then
test again.
(12)The reading on the ammeter should be above
the limit value. If the reading is below the limit
value and the generator output wire is normal,
remove the generator from the engine and check
the generator.(13)Run the engine at idle speed after the test.
(14)Turn the ignition switch to the OFF position.
(15)Disconnect the negative battery cable.
(16)Disconnect the ammeter, voltmeter and
tachometer.(17)Connect the generator output wire to the
generator “B” terminal.
(18)Connect the negative battery cable.
TSB Revision

Downloaded from www.Manualslib.com manuals search engine ENGINE ELECTRICAL - Charging Svstem16-9REGULATED VOLTAGE TEST
\:
b
Ignitionswitch (IGl)Generator
This test determines whether the voltage regulator
is correctly controlling the generator output voltage.
(1) Always be sure to check the following before
the test.l Generator installation
lCheck to be sure that the battery installedin the vehicle is fully charged. (Refer to
GROUP 54 - Battery.)l Generator drive belt tension (Refer to
GROUP 00 - Maintenance Service.)l Fusible link
l Abnormal noise from the generator while
the engine is running(2) Turn the ignition switch to the OFF position.
(3) Disconnect the negative battery cable.
(4) Connect a digital-type voltmeter between the
generator “S” terminal and the ground. (Connect
the
(+) lead of the voltmeter to the “s” terminal,
and then connect the (-) lead of the voltmeter
to a secure ground or to the battery (-) terminal.)
(5) Disconnect the generator output wire from the
generator
“B” terminal.(6) Connect a DC test ammeter with a range of
O-100A in series between the “B” terminal andthe disconnected output wire. (Connect the
(+) lead of the ammeter to the “B” terminal,
and then connect the (-) lead of the ammeter
to the disconnected output wire.)
(7) Connect a tachometer. (Refer to GROUP 11
- On-vehicle Service.)
(8) Reconnect the negative battery cable.
VOLTAGE REGULATION TABLE
Ammeter
- Load
6EN1029
(9) Turn the ignition switch to the ON position and
check that the reading on the voltmeter is equal
to the battery voltage.
NOTE
If the voltage is 0 V, the cause is probably an
open circuit in the wire or fusible link between
the generator
“S” terminal and the battery (+)
terminal.
(1O)Check to be sure that all lights and accessories
are off.
(11) Start the engine.(12)lncrease the engine speed to 2,500
r/min.
(13)Read the value displayed on the voltmeter when
the current output by the generator becomes
10A or less.
(14)lf the voltage reading conforms to the value
in the voltage regulation table, then the voltage
regulator is operating normally.If the voltage is outside the standard value,
there is a malfunction of the voltage regulator
or of the generator.
(15)After the test, lower the engine speed to the
idle speed.
(16)Turn the ignition switch to the “OFF” position.
(17)Disconnect the negative battery cable.
(18)Disconnect the ammeter, voltmeter and
tachometer.(19)Connect the generator output wire to the
generator “B” terminal.
(20)Connect the negative battery cable.
Inspection
terminal
Terminal “S”
Voltage regula-Standard value Inspection
torambient (V)terminal
temperature
(“C PI)-20 (-4)14.2-15.4
Terminal “S”
20 (68)13.9-14.9
TSB Revision
Voltage regula- Standard value
torambient (V)
temperature(“c
PI)
60 (140)13.4-14.5
80 (176)13.1-14.5
I

Downloaded from www.Manualslib.com manuals search engine ENGINE ELECTRICAL - Charqinq SystemWAVE-FORM CHECK USING AN ANALYZER
II
MEASUREMENT METHOD
Connect the analyzer special patterns pick-up to the generator
:L.J ,
B terminal.
I“B” terminalZ7ELOlSlI
STANDARD WAVE-FORM
Observation Conditions
FUNCTION1 SPECIAL PATTERNS
IPATTERN HEIGHTVARIABLEAdjust while viewing the
wave-
{
IEngine speedCurb idle speed
-
0.4
0.2
IVoltage atgenerator 0 p7r-\fTfTfi/\AJ\ I+ h A fi 4 n rB terminal-0.2
-
-0.4t
lime
27ELOl15
1NOTE
Furthermore, the voltage wave-form of the generator B terminal
can undulate as shown at left. This wave-form is produced
when the regulator operates according to fluctuations in the
generator load (current), and is normal for the generator.
TSB Revision

Downloaded from www.Manualslib.com manuals search engine ENGINE ELECTRICAL - Charging System16-11
ABNORMAL WAVE-FORMS EXAMPLES
NOTE
1.The size of the wave-form patterns differs largely depending on the adjustment of the variable knob
on the analyzer.
2.Identification of abnormal wave-forms is easier when there is a large output current (regulator is not
operating). (Wave-forms can be observed when the headlights are illuminated.)
3.Check the conditions of the charge light (illuminated/not illuminated) also, and carry out a total check.
Abnormal wave-formsProblem cause
Example 1l Open diode
AALZELOlZO
Example 20 Short in diodeZ7EL0121
Example 30Broken wire in statorcoil
27EL0122
Example 40Short in stator coil
Z7EL0123
Example 5
1 r2rrirl
0 Open supplementarydiode
27EL01244t this time, the charge light is illuminated.
TSB Revision

Downloaded from www.Manualslib.com manuals search engine ENGINE ELECTRICAL - Charging System
h\Z3ELOlO
\23ELOllINSPECTION
ROTOR
(1) Check field coil for continuity. Check to ensure that there
is continuity between slip rings.If resistance is extremely small, it means that there is
a short. If there is no continuity or if there is short circuit,
replace rotor assembly.
Resistance value : Approx. 3-5 Q
(2) Check field coil for grounding. Check to ensure that thereis no continuity between slip ring and core. If there is
continuity, replace rotor assembly.
STATOR
(1) Make continuity test on stator coil. Check to ensure that
there is continuity between coil leads.
If there is no continuity, replace
stator assembly.
(2) Check coil for grounding. Check to ensure that there is
no continuity between coil and core. If there is continuity,
replace stator assembly.
RECTIFIERS
(1) Positive Rectifier Test
Check for continuity between positive rectifier and stator
coil lead connection terminal with a circuit tester. If there
is continuity in both directions, diode is shorted. Replace
rectifier assembly.
TSB Revision

Downloaded from www.Manualslib.com manuals search engine ENGINE ELECTRICAL - Charging System16-17
Limit line
WELO
,Soldered
27EL0014
(2) Negative Rectifier Test
Check for continuity between negative rectifier and stator
coil lead connection terminal. If there is continuity in both
directions, diode is shorted, and rectifier assembly must
be replaced.
(3) Diode Trio Test
Check three diodes for continuity by connecting an amme-
ter to both ends of each diode. If there is no continuity
in both directions, diode is faulty and
heatsink assembly
must be replaced.
BRUSH REPLACEMENT
(1) Replace brush by the following procedures if it has been
worn to limit line.
(2) Unsolder pigtail and remove old brush and spring.
(3) Install brush spring and new brush in brush holder.(4) Insert the brush to where there is a space 2 to 3 mm
(.079 to .118 in.) between the limit line and the end of
the brush holder.
TSB Revision

Downloaded from www.Manualslib.com manuals search engine ENGINE ELECTRICAL - Starting System16-23
OPERATION
L
0For models equipped with the M/T, the clutch
pedal position switch contact is switched OFF
when the clutch pedal is depressed; when the
ignition switch is then switched to the “ST’ posi-tion, electricity flows to the starter relay and
the starter motor, the contact (magnetic switch)of the starter is switched ON and the starter
motor is activated.
NOTEIf the ignition switch is switched to the “ST
position without the clutch pedal being de-
pressed, electricity flows to the starter relay
(coil), the clutch pedal position switch (contacts)
and to ground, with the result that the contacts
of the starter relay are switched OFF, and, be-
cause the power to the starter motor is thereby
interrupted, the starter motor is not activated.lFor models equipped with the
AIT, when the
ignition switch is switched to the “ST’ position
while the selector lever is at the “P” or “N” posi-
tion, the contact (magnetic switch) of the starter
is switched ON and the starter motor is activated.
TROUBLESHOOTING HINTSThe starter motor does not operate at all.
l Check the starter (coil).
lCheck for poor contact at the battery terminals
and starter.l Check Park/Neutral position switch.
l Check clutch pedal position switch.
l Check starter relay.
l Check theft-alarm starter relay.
l Check key reminder switch.
i
/’
L&J
Fieldcoil wire
Iii?Stopper
IPinion gap
PinionZ6EL003
STARTER MOTORREMOVAL AND INSTALLATION
Refer to GROUP 22
- Manual Transaxle, or GROUP 23 -
Automatic Transaxle.INSPECTION
PINION GAP ADJUSTMENT(1) Disconnect field coil wire from M-terminal of magnetic
switch.
(2)Connect a 12 V battery between S-terminal and M-terminal.(3) Set switch to “ON”, and pinion will move out.
Caution
This test must be performed quickly (in less than 10
seconds) to prevent coil from burning.(4) Check pinion to stopper clearance (pinion gap) with a
feeler gauge.
Standard value: 0.5-2.0 mm (.020-,079 in.)
TSB Revision

Downloaded from www.Manualslib.com manuals search engine ENGINE ELECTRICAL - Starting System16-25
L
Field coil wire27EL0021216Fo264
00002526
MAGNETIC SWITCH RETURN TEST(1) Disconnect field coil wire from M-terminal of magnetic
switch.(2) Connect a 12 V battery between M-terminal and body.
Caution
This test must be performed quickly (in less than 10
seconds) to prevent coil from burning.(3) Pull pinion out and release. If pinion quickly returns to
its original position, everything is in order. If it doesn’t,
replace magnetic switch.
Caution
When pulling out the pinion, be careful not to have
your finger pinched.
STARTER RELAY(1) Remove the starter relay from the relay box.
(2)Connect battery to terminal 2 and check continuity between
terminals with terminal 4 grounded.
Power is supplied3-4 terminals
3-5 terminalsNo continuity
Continuity
/ 3-4 terminals / Continuity 1
Power is not
supplied3-5 terminals
l-2 terminalsNo continuity
Continuity
i
TSB Revision