Service manual

G420F(FE) Service Manual Chapter 4. Engine Electrical System 133
2) Inspect the drive belt for tension.
(See “Engine body” )
2. Turn the ignition switch OFF.
3. Disconnect the battery ground cable.
4. Disconnect the alternator output wire from the
alternator “B” terminal.
5. Connect a DC ampere meter (0-100V) between
“B” terminal and the disconnected output wire.
Connect (+) lead wire to the terminal “B” and (-)
lead wire to the disconnected output wire.
NOTE: Do not use clips or equivalent owing to high
current and Use bolts and nuts to tighten each
connecting part securely.
6. Connect a volt meter(0-20V) between “B” terminal
and the ground.
Connect (+) lead wire to the alternator “B” terminal
and (-) lead wire to the proper position.
7. Connect the engine tachometer and then battery
ground cable.
8. Be sure that the hood is opened.
Test
1. Be sure that voltmeter reading is identified with
battery voltage.
If voltmeter reading is 0V, it means short circuit of
wire between “B” terminal and the battery (-)
terminal, fusible link cut off or ground fault.
2. Turn the headlight ON and start the engine.
3. With the engine running at 2,500 rpm, turn ON the
high beam headlights, place the heater blower
switch at ”HIGH” measure the maximum output
current using a ammeter.
NOTE: This test should be done as soon as
possible to measure the exact maximum current
because output current drops rapidly after starting
the engine.
Result
1. Ammeter reading should be higher than the limit.
If the reading is low even though the alternator
output wire is normal, remove the alternator from
the vehicle and inspect it.
Output current limit 70% of rated current
NOTE: The rated output current is represented on
the name plate in the alternator body.
Output current varies according to electrical load or
temperature of the alternator, so during test, lack of
electrical load causes impossibility of measuring the
rated output current. In this case, turn on headlight
to induce the battery discharging or turn on other
lights to increase the electrical load. If alternator
temperature or ambient temperature is too high, it is
impossible to measure the rated output current, so
prior to re-test, necessarily drop the temperature.
Ambient temperature
of voltage regulator(℃)
Voltage adjust(V)
-20 14.2 ~ 15.4
20 13.8 ~ 15.0
60 13.4 ~ 14.6
80 13.2 ~ 14.4
2. After test, adjust the engine speed at idle and turn
the light and ignition switch OFF.
3. Disconnect the battery ground cable.
4. Disconnect the ammeter and voltmeter.
5. Connect the alternator output lead wire to the
alternator “B” terminal.
6. Connect the battery ground cable.