Onan DJA Series User Manual

ALTERNATOR TROUBLESHOOTING
Trouble in the charging system will be indicated by a weak
or discharged battery.
1. Charge battery and check its condition to be sure
battery is serviceable. Charging system test requires
a tully charged battery.
2. Connect voltmeter across battery - start engine and
operate at 1800 - 3600rpm. The voltmeter should ,
register 13.4 -14.05 volts.
If voltage is below 13.4volts install new output control,
and retest. Be sure output control has good clean ground
connection and the wire connector is properly seated.
'When meter reads 14.05 volts no further testing
is required. When new output control is installed and
meter does not register 13.4volt minimum then proceed
to test stator group as follows:
ay
To determine if the alternator is charging the battery, use
a HOvolt -100 or 150watt light bulb in a socket with leads.
Disconnect the output control and connect the leads from
the lOOvolt bulb across the two yellow leads from the
alternator. Start .the engine and operate at ISOOrpm. The
light bulb will show a d im light and at 3600 rpm the light
bulb will be fairly bright. This method of testing will
require a charged battery for starting the engine.
If the HOvolt light bulb does not indicate a charge, use
an ohmmeter and check out stator coil using the following
procedure with engine stopped.
TEST INSTRUMENT
Simpson Model 260 V.O.M. or equivalent. Set voltage selec-
tor switch to DC + . Be sure test meter is in good condition
and if battery powered, that the battery is good. Be sure
your meter is zeroed before each reading and each time you
change scales.
Disconnect connector at voltage regulator.
Zero meter on Rx 1 scale.
Connect meter leads to the two outside terminals of the
female plug (both yellow wires). Meter should read less
than :8-ohms. This checks stator winding for continuity. If
no reading shows on meter, winding is open - replace stata.
To check for grounded stator winding touch red meter lead
to yellow wire plug and other meter lead to metal core.
Meter should read infinity. If meter shows a reading, then
winding is grounded. Replace stator.
FLYWHEEL MAGNET GROUP
This should be treated in the same manner as the standard
magneto flywheel. There is very little testing that can be
done in the field other than to lay a piece of ferrous (iron)
material up against the magnets to be sure they are charged
or to replace the magnet group.
CAUTION
Be sure to check torque oi bolts fastening
magnet ring group to the flywheel.
YELLOW RED BLUE YELLOW
REGULATOR PLUG
29

Onan DJA Series Specifications

General

Brand	Onan
Model	DJA Series
Category	Engine
Language	English