Troubleshooting & repair, Engine alternator test (continued) – Lincoln Electric VANTAGE 400 User Manual

Page 84

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243

238

BACK OF ALTERNATOR

FIGURE F.7 - LEAD LOCATIONS

ENGINE ALTERNATOR TEST (CONTINUED)

TEST PROCEDURE

1. Turn the engine off.

2. Open the engine access door and check the

voltage at the battery terminals. It should be
approximately 12 volts DC.

3. Attach the meter leads to the battery terminals,

being careful to position them so they stay
clear of moving parts while the engine is run-
ning.

4. Place the idle switch in the “HIGH IDLE” posi-

tion, start the engine, and allow it to run at high
idle speed for about 15 to 30 seconds.

5. The meter should read about 13.7 to 14.2

VDC.

6. If the meter reads correctly the engine alterna-

tor is producing adequate power to charge the
battery and this test is complete.

6. If the voltage is significantly higher than the

above values, the alternator is not properly
regulating the battery charging voltage and
should be replaced. If the voltage reads the
same or less than the measurement taken
when the engine was not running, proceed
with the following tests.

7. Turn off the engine, disconnect the meter from

the battery, and open the engine access door
on the left side of the machine.

8. Make sure the idle switch is still in the “high”

position, start the engine, and allow it to run at
high idle speed for about 15 to 30 seconds.

9. Place the negative meter probe on a good

chassis ground, or the negative battery termi-
nal. Place the positive meter probe on the bat-
tery terminal on the back of the alternator.
(Lead #238) See Figure F.7. See Wiring
Diagram.

10. The meter should read about 13.7 to 14.2

VDC.

11. Move the positive probe to the DT terminal on

the back of the alternator. (Lead 243C) See
Figure F7.

12. The meter should read about 13.7 to 14.2

VDC.

13. If the meter reads correctly, check the connec-

tions between the alternator and the battery.
See wiring diagram.

14. If the voltage at both of the above test points

reads the same or less than the battery voltage
measurement taken when the engine was not
running, the alternator is defective. Repair or
replace it.

TROUBLESHOOTING & REPAIR

F-36