Electrical System Quick Checks; Battery Test (Open Circuit Test); Charging System Test; Glow Plug System Test (Groundsmaster 328-D) - Toro Groundsmaster 300 Series Service Manual

Electrical System Quick Checks

Battery Test (Open Circuit Test)

Use a multimeter to measure the voltage between the
battery terminals.
Set the multimeter to the DC volts setting. The battery
should be at a temperature of 60
C). The ignition key should be in the OFF position and
all accessories turned off. Connect the positive (+) me-
ter lead to the positive battery post and the negative (–)
meter lead to the negative battery post. Use the table to
the right to determine charge level of the battery.
Note: This test provides a relative condition of the bat-
tery. Load testing of the battery will provide additional
and more accurate information.

Charging System Test

This is a simple test used to determine if the charging
system is functioning. It will tell you if the charging sys-
tem has an output, but not its capacity.
Use a multimeter set to the DC volts position. Connect
the positive (+) meter lead to the positive battery post
and the negative (–) meter lead to the negative battery
post. Leave the multimeter test leads connected to the
battery and record the battery voltage.
Note: Upon starting the engine, the battery voltage
will drop and then should increase once the engine is
running.
Note: Depending upon the condition of the battery
charge and battery temperature, the charging system
voltage will increase at different rates as the battery
charges.
Start the engine and run at high idle speed. Allow the
battery to charge for at least three (3) minutes. Record
the battery voltage.
Glow Plug System Test (Groundsmaster 328–D)
This is a fast, simple test that can help to determine the
integrity and operation of the Groundsmaster 328–D
glow plug system. The test should be run anytime hard
starting (cold engine) is encountered on a diesel engine
equipped with a glow plug system.
Use a digital multimeter and/or inductive Ammeter (AC/
DC Current Transducer) set to the correct scale. With
the ignition switch in the OFF position, place the amme-
Groundsmaster 300 Series
o o o o
to 100 F (16 to 38
Page 6A – 3
Voltage Measured
12.68 v (or higher)
12.45 v
12.24 v
12.06 v
11.89 v
After allowing the engine to run for at least three (3) min-
utes, battery voltage should be at least 0.5 volts higher
than initial battery voltage (see example in table to the
right).
Note: While engine is running, if battery voltage ex-
ceeds 16 volts, the regulator in the charging system
should be inspected.
After allowing the engine to run for at least three (3) min-
utes, if battery voltage does not increase at least 0.5
volts, additional testing of the battery and/or charging
system should be performed.
Acceptable voltage increase:
Initial Battery Voltage
Battery Voltage after 3 Minute Charge
Difference
ter pickup around the main glow plug power supply wire.
Adjust the meter to read zero (if applicable). Cycle the
glow plug system at least two times (per instructions in
Traction Unit Operator's Manual) and record the final re-
sults.
The Groundsmaster 328–D glow plug system should
have a reading of approximately 27 Amps. If low current
reading is observed, one (or more) glow plugs is faulty.
Battery Charge Level
Fully charged (100%)
75% charged
50% charged
25% charged
0% charged
= 12.25 v
= 12.80 v
= +0.55 v
Electrical System (Rev. G)