Onan NHC Series Operator's/Service Manual And Parts Catalog page 110

NOTE: Poor contact at the battery cable con-
nections is often a source of trouble. Make sure
battery cables are in good condition and that
contacting surfaces are clean and tightly con-
nected. Do not reverse battery, leads. Use recom-
mended battery tools when disconnecting leads to
avoid mechanical battery damage.
2. Make sure the two alternator .stator leads are not
shorted together.
3. Check mounting of regulator-rectifier, case to unit.
It should provide a good electrical ground with
clean, bright surfaces.
4. Output control plug (connector) musf be pushed in
so it bottoms solidly in the receptacle. Keep i t
clean and tight.
IMPORTANT: Charging system tests require a
fully charged battery.
Testing: With the engine running between 1800-2600
rpm, observe the panel ammeter, (if not already
equipped, connect a test ammeter.) If no Charging is
evident, proceed with the NO CHARGE TEST given
as follows. If ammeter shows a constant higher charge
rate, follow the HIGH CHARGE RATE TEST procedure.
No Charge Test: Perform as follows:
1. Check the E+ to ground voltage using a DC
voltmeter.
2. If voltmeter reads 13.8volts or higher, add a load
to system (e.g. headlights) to reduce battery
voltage to below 13.6 volts.
3. Observe ammeter. If charge rate increases, consi-
der the system as satisfactory. I f charge rate does
not increase, proceed with testing.
4. Disconnect plug from regulator-rectifier and test
the AC voltage at the plug with engine running
near 3600rpm. If AC voltage reads less than
28 volts, replace the stator. I f AC voltage is more
than 28volts, replace the regulator-rectifier assem-
bly.
High Charging Rate Test: Perform this test as f o l l o w s :
. 1 . Check B+ to ground voltage with a DC voltmeter.
2. If voltmeter reads over 14.7 volts, replace regulator-
rectifier assembly.
3. If reading is under 14.7 volts the system is proba-
bly okay. Recheck the battery and connections. I f
the battery does have a low charge, but accepts
recharging, system is okay.
P O I N T E R ON TIMING
H O L E IN F L Y W H E E L .
A L T E R N A T O R R O T O R
( P A R T O F F L Y W H E E L A S S E M B L Y )
SCREEN B O L T
TIMING H O L E
THROUGH
F L Y W H E E L
S T A T O R
R E G U L A T O R - R E C T I F I E R
F I G U R E 2 5 . F L Y W H E E L A L T E R N A T O R
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