CHARGING SYSTEM
TSB Revision
ENGINE ELECTRICAL
16-8
ON-VEHICLE SERVICE
GENERATOR OUTPUT LINE VOLTAGE DROP TEST
M1161000900669
Required Special Tool:
MB991958: Scan Tool (MUT-III Sub Assembly)
• MB991824: V.C.I.
• MB991827: MUT-III USB Cable
• MB991910: MUT-III Main Harness A
This test determines whether the wiring from the
generator "B" terminal to the positive battery terminal
(including the fusible link) is in good condition or not:
WARNING
Battery posts, terminals and related acces-
sories contain lead and lead compounds.
WASH HANDS AFTER HANDLING.
1. Always be sure to check the following before the
test.
• Generator installation
• Generator drive belt tension (Refer to GROUP
00, General
− Maintenance Service − Drive Belts
(For Generator, Power Steering Pump and Air
Conditioning) (Check)
P.00-45
.)
• Fusible link
• Abnormal noise from the generator while the
engine is running.
2. Turn the ignition switch to the "LOCK" (OFF)
position.
3. Disconnect the negative battery cable.
4. Connect a clamp-type DC test ammeter with a
range of 0
− 100 A to the generator "B" terminal
output wire.
NOTE: The way of disconnecting the generator
output wire and of connecting the ammeter is pos-
sibly not found the problem that the output current
is dropping due to the insufficient connection
between terminal "B" and the output wire.
5. Connect a digital-type voltmeter between the
generator "B" terminal and the positive battery
terminal. (Connect the positive lead of the
voltmeter to the "B" terminal, and then connect the
negative lead of the voltmeter to the positive
battery cable.)
6. Reconnect the negative battery cable.
7. Connect an engine tachometer or scan tool
MB991958.
8. Leave the hood open.
9. Start the engine.
AK203361AC
GENERATOR
AMMETER
(CLAMP-TYPE)
VOLTMETER
(DIGITAL-TYPE)
"B" TERMINAL
BATTERY