Toro Groundmaster Series Service Manual page 238

Testing Relays with 5 Terminals
Electrical System: Testing the Electrical Components
to the engine starter solenoid and the engine fuel solenoid via the delay timer.
For model 31902 and 31903 machines, the start interlock relay sends power
to the engine ECU. The start interlock relay is energized by the TDM.
•
The Exhaust Gas Recirculation (EGR) relay is used to provide current to
the engine EGR valve (models 31902 and 31903 only). The EGR relay is
energized by the Yanmar engine ECU.
•
The start relay supplies power to the engine starter (models 31902 and 31903
only). The start relay is energized by the Yanmar engine ECU.
•
The AC condenser fans relay provides current to both of the condenser fans
and the AC clutch relay (models 31903 and 31909 only). The AC condenser
fans relay is energized by the air conditioning system thermostat.
•
The AC switch signal relay is part of the standard cab rooftop harness, but is
not used on Groundsmaster 3310 machines.
•
The AC clutch relay and the AC condenser fans relay must be energized to
engage the compressor clutch (models 31903 and 31909 only). The AC
clutch relay is energized by the thermostat as long as the minimum AC
system pressure exists (AC pressure switch closed).
Refer to Figure 93 for this procedure.
1. Park the machine on a level surface, lower the cutting unit (or attachment),
engage the parking brake, set the key switch to the O
the key from the key switch.
2. Disconnect the ground cable at the battery; refer to
the Battery (page 6–64).
3. Remove the operator's console covers; refer to
Operator's Console Covers (page
4. Locate the relay that is to be tested and disconnect the wire harness
connectors from the relay. Check the relay and the harness connector for
damage or corrosion and clean or repair if necessary.
g256780
7–23).
Figure 98
Relay with 5 terminals
Page 6–46
position and remove
FF
Removing and Installing
Removing and Installing the
Groundsmaster ® 3200, 3300 and 3310
19240SL Rev A