Charging System Alternator Tests - Polaris MS4000 Service And Owner's Manual

ELECTRICAL

Charging System Alternator Tests

Three tests can be performed using a multi-meter to determine
the condition of the stator (alternator).
Y1
Y2
TEST 1: Resistance Value of Each Stator Leg
1. Measure the resistance value of each of the three stator
legs: Y1 to Y2, Y1 to Y3, and Y2 to Y3.
Each test should measure: 0.19Ω ± 15%
Connect Meter
Test
Leads To:
Battery Charge Coil
Battery Charge Coil
Battery Charge Coil
NOTE: If there are any significant variations in ohm
readings between the three legs it is an indication
that one of the three stator legs maybe weak or
failed.
TEST 2: Resistance Value of Each Stator Leg to Ground
1. Measure the resistance value of each of the stator legs to
ground: Y1 to Ground, Y2 to Ground, Y3 to Ground.
Each test should measure: Open Line (OL)
Connect Meter
Test
Leads To:
Y1, Y2, or Y3
Battery Charge Coil
NOTE: Any measurement other than Infinity (open)
will indicate a failed or shorted stator leg.
10.24
Y3
Ohms Reading
Y1 to Y2 0.19Ω ± 15%
Y1 to Y3 0.19Ω ± 15%
Y2 to Y3 0.19Ω ± 15%
Ohms Reading
Open Line
to Ground (Infinity)
TEST 3: Measure AC Voltage Output of Each Stator Leg at
Charging RPM
1. Set the selector dial to measure AC Voltage.
2. Start the engine and let it idle.
3. While holding the engine at a specified RPM, separately
measure the voltage across each 'leg' of the stator by
connecting the meter leads to the wires leading from the
alternator (Y1 to Y2, Y1 to Y3, Y2 to Y3).
4. Refer to the following table for approximate AC Voltage
readings according to RPM. Test each leg at the specified
RPM in the table.
Example: The alternator current output reading should be
approximately 18 VAC at 1300 RPM between each 'leg'.
NOTE: If one or more of the stator leg output AC
voltage varies significantly from the specified value,
the stator may need to be replaced.
RPM Reading
1300
3000
5000
AC Voltage (VAC) Reading
18 VAC ± 25 %
42 VAC ± 25 %
64 VAC ± 25 %