A
poor batteQ causes problems and should be
checked first during electrical system
troubleshooting
or
maintenance. The better the care,
the longer all components will last and the more
profitable, trouble-free service you’ll receive.
Regulator-Rectifier
To see if the regulator is performing satisfactorily,
place a DC voltmeter across the battery terminals with
the engine NOT running. Record this voltage. Then
start the engine and accelerate to afast idle
(1
800
rpm
or
higher). If the voltage does not rise from original
reading after a few minutes, the system is not
operating
properly, and the regulator should be
suspected. However, check the alternator output
before concluding that the regulator is at fault.
TEST
Alternator
To see if alternator is producing voltage, unplug
connector and insert an
AC
voltmeter into two stator
output leads (yellow). Start engine and accelerate to
approximately
.I800
rpm. Voltmeter should read ap-
proximately 17-30 AC volts. If voltage is considerably
less than these figures, either the alternator stator or
rotating magnet group is defective. Test stator win-
dings with an ohmmeter (engine not running). Stator
winding values are usually less than one ohm. If
readings are within limits, then the magnet group is
defective.
VALUE
TESTING
To
check alternator output, connect an ammeter
between the red terminal on the rectifier and the
ignition switch. With the engine running at
1
,800-rpm,
the ammeter should indicate about 8-amperes into a
fully discharged battery, and progressively less as the
battery becomes charged. The regulator switches
from high to
lowchargeatabout14-1/2voltsandfrom
low to high at about 13 volts. Current at low charge
should be about 2-amperes. If output is unsatisfac-
tory, do the following tests.
Rotor:
To
test for magnetism in the rotor, merely hold
a piece of steel close to the magnet. If the steel is
strongly attracted, the rotor is satisfactory.
If
not,
replace the flywheel magnet group. Strength of the
magnet
is
a basic quality that will not change much
over a period of time.
Be sure to check torque
of
bolts fastening
magnet ring group to the flywheel.
Regulator-Rectifier Test (Begin Spec
T):
1.
Charge battery and check its condition to besure
it is serviceable. See Table 3.
Charging system tests require a fully charged battery.
Battery voltage
-
unit
not running
Battery voltage with
unit running at 1800 rpm
or more
(fully
charged
battery)
AC voltage from stator
with plug disconnected
and unit running at
about 1800 rpm
Ohmmeter reading at plug
when checking two AC
stator leads
-
unit not
running.
12 volts DC
13.4
-
14
volts DC
17 volts AC
i
10%
Less than
.8 Ohms
2. Connect a voltmeter across battery. Start engine
and operate between
1800
and 3600 rpm. The
voltmeter should read 13.4 to
14
volts.
3. If voltage is below 13.4 volts, install a new
regulator-rectifier and re-test. Be sure regulator-
rectifier has a good clean ground connection and
that the wire connector is properly seated.
4.
When meter reads
13.4
volts, no further testing is
required. If new regulator-rectifier has been in-
stalled and meter does not register 13.4 volts
minimum, then proceed to test the stator group.
Flywheel Stator Test
-
Engine Running:
With engine running at
1800
rpm, disconnect connec-
tor at regulator and insert an
AC
voltmeter between
the two yellow wires. The
AC
voltage should read
approximately 17 volts
or
higher.
Flywheel StatorTest
-
Engine Not Running:
Use a Simpson Model 270 V.O.M. or equivalent for
testing stator. Set voltage selector switch to DC+. Be
sure test meter is in good condition and if battery
powered, that the battery is good. Be sure the meter is
zeroed before each reading and each time you
change scales.
1.
Disconnect connector plug at regulator. Zero
meter on
Rxl
scale.
2. Connect meter leads to the two outside terminals
of the female plug (both yellow wires). Meter
should read less than
.8
ohms. This test checks
stator winding for continuity.
If
no reading shows
on meter, winding is open. Replace stator.
3. To check for grounded stator winding, touch red
meter lead to yellow wire plug and other meter
lead to meta!-coIer Meter should read infinity. If
53
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