Lincoln Electric RED-D-ARC DX450 Service Manual page 74

F-30
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 that 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 the test is complete.
7. If the voltage is significantly higher than the
above values, the alternator is not properly reg-
ulating 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 fol-
lowing tests.
TROUBLESHOOTING AND REPAIR
8. With the engine running and the RUN/STOP
switch in the "RUN" position, check the voltage
at Lead 232I. It should be the same as the bat-
tery voltage. If it is not present, check for faulty
connections. See Wiring Diagram.
9. 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.
Place the negative meter probe on a good
10
.
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 Wiring Diagram.
The meter should read about 13.7 to 14.2
11.
VDC.
12. Move the positive probe to the Lead 26GV on
the back of the alternator.
13. The meter should read about 13.7 to 14.2
VDC.
14. If the meter reads correctly, check the connec-
tions between the alternator and the battery.
See wiring diagram.
15. 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.
DX450
F-30