Wacker Neuson GP 3800A, Repair Manual

Page: 106 / 130

Troubleshooting GP Repair
wc_tx000548gb.fm
102
6.23 Checking Auto Idle Circuitry Between Generator and Fuse
See Graphic: wc_gr003131
Voltage may be prevented from reaching the 5A fuse by a faulty
rectifier or by a faulty DC winding. The auto idle circuit may also be
malfunctioning due to faulty sensing wires. To check the circuit, carry
out the following procedures:
6.23.1 Stop the generator.
6.23.2 Remove the two screws which secure the end cover to the generator
and remove the end cover.
6.23.3 To check the rectifier
(a)
, remove the connector plug from the rectifier.
Use the diode scale on your multimeter. Probe the top terminal with
one lead and the bottom terminal with the other. Then, reverse the
leads and conduct the test again. The rectifier should conduct in one
direction and not the other. Check both upper terminals of the rectifier
to the lower terminal of the rectifier in the same manner.
•
If the rectifier is malfunctioning, replace it.
• If the rectifier is functioning, continue.
6.23.4 Remove the plug
(b)
from the stator.
6.23.5 Using the Ohms scale on your multimeter, check the resistance of the
DC winding. Each generator size will have a different value for the
winding resistance. Check the chart in the graphic for the correct
values—use a tolerance of +0.5/-0.0 Ohms.
•
If the correct amount of resistance was not measured, replace
the stator.
• If the correct amount of resistance was measured, the DC wind-
ing is OK; continue.
6.23.6 Remove the screws which secure the control panel to the generator.
6.23.7 Check that the sensing wires are running through the ammeter
(c)
of
the auto idle unit.
6.23.8 Check the continuity of the sensing wires
(d)
from the auto idle unit
through to the generator terminal strip
(e)
.