Onan DJA Series User Manual

FLYWHEEL ALTERNATOR
MODELS BEGINNING WITH SPEC T
The flywheel alternator is a permanent magnet alterna-
tor and uses a solid-state voltage regulator-rectifier
for controlling output (Figure 33).
A 30-ampere fuse "is included in the battery charging
system to protect the alternator in case the battery
cables are accidently reversed. The fuse is. located
behind the air housing door (above injection pump).
Check the fuse before performing any tests.
Weak ignition spark or a discharged battery indicates
trouble in the charging system, but always check the
battery for serviceability first.
Keep these points in mind when testing or servicing
the flywheel alternator:
1. Be sure the output control plug (connector) is
inserted properly. The plug must bottom in recep-
tacle to eliminate any resistance due to a poor
connection. Keep clean and tight.
2. Be sure regulator-rectifier output control has a
good ground connection. Mating surface for mount-
ing must be clean and fasteners tightened properly.
3. Never reverse the battery leads. Reverse polarity
will blow the fuse.
Regulator-Rectifier Tests:
NOTE: The following tests for the regulator-rectifier
require a fully-charged battery.
T. Connect a voltmeter across the battery. Start the
engine and operate at 2400 rpm.
2. Voltmeter should read 13.4 to 14.0 volts., If it does,
no further testing of the ctiarging system is neces-
sary. If not, install ai new regulator-rectifier and
retest. Be sure it has a good grouhd connection
and the connector is properly seated.
Stator Tests
For testing, use a Simpson 260Multimeter or equivalent.
Be sure test meter and battery, if battery powered, are
in good condition. Check with engine NOT running.
1.
2.
Set voltage selector switch to DC+ and zero meter
on RX1 scale.'
NOTE: Zero the meter beiore each reading and
each time scales are changed.
Unplug the connector and connect the meter leads
to the two terminals of the female plug with the
yellow wires. Meter should read less than 0.8 ohms
if stator has continuity. If meter shows no reading,
winding is open and stator should be replaced.
STATOR FUSEHOLDER WITH
30-AMPERE FUSE
ROTOR
REGULATOR-RECTIFIER
ASSEMBLY
CONNECTOR
FIGURE 33. FLYWHEEL ALTERNATOR (BEGINNING WITH SPEC T)
31

Onan DJA Series Specifications

General

Brand	Onan
Model	DJA Series
Category	Engine
Language	English