Main Power, Glow, Start (4Wd Machines) And Cab Power (4Wd Machines With Operator Cab) Relays - Toro Groundsmaster 360 Service Manual

Main Power, Glow, Start (4WD Machines) and Cab Power (4WD Machines with Operator
Cab) Relays
The Groundsmaster 360 electrical system includes
identical relays for current control. The main power,
glow, start (4WD machines) and cab power (4WD ma-
chines with operator cab) relays are attached to the air
cleaner bracket near the rear steering cylinder (Fig. 60).
The wire harness is attached to these relays with four (4)
wire connectors. Relays can be identified by a tag on the
wire harness.
The main power relay is used to provide current to the
fuse blocks. When the ignition switch is in the RUN or
START position, the main power relay is energized.
The glow relay is used to provide current to the engine
glow plugs when the relay is energized. On 2WD ma-
chines, the glow relay is energized by the glow control-
ler. On 4WD machines, the Toro Electronic Controller
(TEC) provides current to energize the glow relay.
The start relay on 4WD machines is used in the engine
starting circuit. When energized by the TEC controller,
the start relay provides a current path to energize the en-
gine starter solenoid.
The cab power relay on 4WD machines with cab is used
to provide current to the operator cab electrical circuits.
The cab power relay is energized when the main power
relay is energized.
On 4WD machines, the glow relay and the start relay
along with their circuit wiring should be tested as a TEC
controller output with the Diagnostic Display before dis-
connecting and testing the relay (see Special Tools and
Troubleshooting in this chapter).
Testing
1. Park machine on a level surface, lower cutting deck,
stop engine, apply parking brake and remove key from
ignition switch. Raise and support hood.
2. Make sure ignition switch is in the OFF position. Dis-
connect wire harness electrical connector from relay
that is to be tested. Remove relay from air cleaner brack-
et for easier testing.
NOTE: Prior to taking small resistance readings with a
digital multimeter, short the meter test leads together.
The meter will display a small resistance value (usually
0.5 ohms or less). This resistance is due to the internal
resistance of the meter and test leads. Subtract this val-
ue from the measured value of the relay being testing.
3. Verify coil resistance between terminals 85 and 86
with a multimeter (ohms setting). Resistance should be
approximately 72 ohms.
Electrical System
4. Connect multimeter (ohms setting) leads to relay ter-
minals 30 and 87. Ground terminal 86 and apply +12
VDC to terminal 85. The relay should make and break
continuity between terminals 30 and 87 as +12 VDC is
applied and removed from terminal 85.
5. Disconnect voltage and leads from the relay termi-
nals.
6. Secure relay to air cleaner bracket and connect wire
harness electrical connector to relay after testing is
completed.
7. Close and secure hood.
1. Relay location
Page 5 - - 46
1
Figure 60
2. Rear steering cylinder
85
87
86 87
85 30
Figure 61
Groundsmaster 360
2
30
86