Mitsubishi Electric Lancer Evolution-VII Workshop Manual page 1061

16-6
This test determines whether the alternator output
current is normal.
(1) Before the test, always be sure to check the
following.
Alternator installation
D
Battery (Refer to GROUP 54 - Battery.)
D
NOTE
The battery should be slightly discharged.
The load needed by a fully-charged battery
is insufficient for an accurate test.
Alternator drive belt tension
D
(Refer to GROUP 11 - On-vehicle Service.)
Fusible link
D
Abnormal noise from the alternator while
D
the engine is running.
(2) Turn the ignition switch to the "LOCK" (OFF)
position.
(3) Disconnect the negative battery cable.
(4) Disconnect the alternator output wire from the
alternator "B" terminal. Connect a DC test
ammeter with a range of 0 - 100 A in series
between the "B" terminal and the disconnected
output wire. (Connect the (+) lead of the
ammeter to the "B" terminal. Connect the ( - )
lead of the ammeter to the disconnected output
wire.)
Caution
Never use clips but tighten bolts and nuts
to connect the line. Otherwise loose
connections (e.g. using clips) will lead to
a serious accident because of high current.
NOTE
An inductive-type ammeter which enables
measurements to
disconnecting the alternator output wire should
be recommended.
(5) Connect a voltmeter with a range of 0 - 20 V
between the alternator "B" terminal and the
earth. (Connect the (+) lead of the voltmeter
to the "B" terminal, and then connect the ( - )
lead of the voltmeter to the earth.)
(6) Connect the negative battery cable.
(7) Connect a tachometer or the MUT-II.
(Refer to GROUP 11 - On-vehicle Service.)
(8) Leave the hood open.
(9) 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 alternator "B" terminal and the battery (+)
terminal.
ENGINE ELECTRICAL -
be taken without
Charging System
(10)Turn the light switch on to turn on headlamps
and then start the engine.
(11)Immediately after setting the headlamps to high
beam and turning the heater blower switch to
the high revolution position, increase the engine
speed to 2,500 r/min and read the maximum
current output value displayed on the ammeter.
Limit: 70 % of normal current output
NOTE
For the nominal current output, refer to the
D
Alternator Specifications.
Because the current from the battery will
D
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.
The current output value will depend on
D
the electrical load and the temperature of
the alternator body.
If the electrical load is small while testing,
D
the specified level of current may not be
output even though the alternator is normal.
In such cases, increase the electrical load
by leaving the headlamps turned on for
some time to discharge the battery or by
using the lighting system in another vehicle,
and then test again.
The specified level of current also may not
D
be output if the temperature of the alternator
body or the ambient temperature is too
high. In such cases, cool the alternator 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 alternator output wire is normal,
remove the alternator from the engine and
check the alternator.
(13)Run the engine at idle after the test.
(14)Turn the ignition switch to the "LOCK" (OFF)
position.
(15)Remove the tachometer or the MUT-II.
(16)Disconnect the negative battery cable.
(17)Disconnect the ammeter and voltmeter.
(18)Connect the alternator output wire to the
alternator "B" terminal.
(19)Connect the negative battery cable.