ELECTRICAL
9-18
CURRENT DRAW - KEY OFF
Do not connect or disconnect the battery cable or
ammeter with the engine running. Damage
to light bulbs and speed limiter.
Connect an ammeter in series with the negative battery cable.
Check for current draw with the key off.
If the draw is excessive, loads should be disconnected from the
system one by one until the draw is eliminated. Check
component wiring as well as the component for partial shorts
to ground to eliminate the draw.
Current Draw - Key Off:
Maximum of .02 DCA (20 mA)
The “break even” point of the charging system is the point at
which the alternator overcomes all system loads (lights, etc.)
and begins to charge the battery.
Depending on battery condition and system load, the
break-even point may vary slightly. The battery should
charged before performing this test.
◎ Clamp an inductive ammeter or connect an ammeter (set to
DC amps) in series between the negative battery cable and
terminal.
◎ Connect a tachometer according to manufacturer’s
instructions.
◎ With engine off and the key and kill switch in the
ON position, the ammeter should read negative amps (battery
discharge). Reverse meter leads if a positive reading is
indicated.
◎ Shift transmission into neutral and start the engine.
If using an ammeter in series, start engine with
kick-start only.
◎ Turn headlight on high beam and apply the brake light.
Increase engine RPM while observing ammeter and
tachometer.
◎ Note RPM at which the battery starts to charge (ammeter
indication is positive).
◎ With lights and other electrical load off, this should occur
at approximately 1500 RPM or lower.
◎ Turn the lights on and lock parking brake to keep brake
light on.
◎ Repeat test, observing ammeter and tachometer. With
lights on, charging should occur at or below 2000 RPM.
ALTERNATOR OUTPUT TEST (AC AMP)
This test measures AC amperage from the alternator.
This test simulates a “full load” on the
not perform this test longer than required
reading or the alternator stator windings may
overheat. Do not exceed idle rpm during this test.
To Calculate Available Alternator Output
I=P/E, 150W / 12V = 12.5 Amps I =
I = Current in Amps
P = Power in Watts
E = Electromotive Force (Volts)
Alternator Current Output:
Minimum of 5 AC Amps
◎ Maximum alternator output will be indicated on the meter.
It is not necessary to increase engine RPM above idle.
◎ Place the red lead on the tester in the 10A jack.
◎ Turn the selector dial to the AC amps position.
◎ Connect the meter leads to the wires leading from the
alternator (see schematic for proper wiring colors).
◎
Start the engine and let it idle. Reading should be
a minimum of 5A at idle.
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