Starter No-Load Test - Toro Workman 3000 Series Service Manual

Starter No–Load Test
1. Connect a 12 volt battery, ammeter and voltmeter to
the starter as shown.
2. Starter motor should turn smooth and steady when
battery is connected with a maximum resistance value.
Adjust variable resistance so voltmeter indicates stan­
dard value. If current and RPM are out of specification
after this adjustment, troubleshoot according to test re­
sults below.
Standard value
Terminal voltage
Current
Speed
No–Load Test Results
Symptom
Large current with low RPM
(torque also low).
Large current with no
rotation.
No current flowing with no
rotation.
Small current with low RPM
(torque also low).
Large current with high
RPM (torque low).
Liquid Cooled Gas Engine
11.5 V
50 A or less
6000 RPM or more
Possible cause
Contaminated bearing.
Armature coil rubbing pole piece.
Armature and field coil grounding.
Armature coil shorting.
Solenoid switch grounding.
Armature and field coil grounding.
Seized bearing.
Broken armature and field coils.
Broken brush and pigtail.
Improper contact between brush
and commutator.
Improper field coil connection
(NOTE: Open or improperly
connected shunt coil only will result
in high RPM.)
Shorted field coil.
Starter
motor
Page 3 – 42
Variable
resistor
Ammeter
A
Battery
V Voltmeter
12V
Figure 62
Workman 3000/4000 Series