Mitsubishi MOTORS Lancer 2004, Workshop Manual

Page: 435 / 638

CHARGING SYSTEM
ENGINE ELECTRICAL 16-7
REGULATED VOLTAGE TEST
M1161001100354
This test determines whether the voltage regulator
correctly controlling the alternator output voltage.
1. Always be sure to check the following before the
test.
•
Alternator installation
•
Check that the battery installed in the vehicle is
fully charged.
(Refer to GROUP 54A
−
Battery
−
On-vehicle
Service
−
Charging P.54A-4 ).
•
Drive belt tension
(Refer to GROUP 11A
−
On-vehicle Service <4G1>
P.11A-7 or GROUP 11C
−
On-vehicle Service
<4G6> P.11C-7 .)
•
Fusible link
•
Abnormal noise from the alternator while the
engine is running
2. Turn the ignition switch to the "LOCK" (OFF)
position.
3. Disconnect the negative battery cable.
4. Use the special tool Alternator test harness
(MB991519) to connect a digital voltmeter
between the alternator "S" terminal and earth
[Connect the (+) lead of the voltmeter to the "S"
terminal, and then connect the (-) lead of the
voltmeter to a secure earth or to the battery (-)
terminal].
5. Connect a clamp-type DC test ammeter with a
range of 0
−
120 A to the alternator "B" terminal
output wire.
NOTE: The way of disconnecting the alternator
output wire and of connecting the ammeter is
possibly not found the problem that the output
current is dropping due to the insufficient
connection between terminal "B" and the output
wire.
6. Reconnect the negative battery cable.
7. Connect a tachometer or the MUT-II/III (Refer to
GROUP 11A
−
On-vehicle Service
−
Idle speed
check <4G1> P.11A-11 or GROUP 11C
−
On-vehicle Service
−
Idle speed check <4G6>
P.11C-11 ).
8. 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 alternator "S" terminal and the battery (+)
terminal.
9. Turn all lamps and accessories off.
10.Start the engine.
11.Increase the engine speed to 2,500 r/min.
12.Read the value displayed on the voltmeter when
the alternator output current alternator becomes
10 A or less.
13.If the voltage reading conforms to the value in the
voltage regulation, then the voltage regulator is
operating normally.
AK300727AB
Battery
Ignition switch
Engine-ECU <M/T>
Engine-A/T-ECU <A/T>
Ammeter (clamp-type)
Load
Black
MB991519
Voltmeter (digital-type)
Red
Yellow
Blue
Alternator
B
FR
L
S
G