Toro Groundsmaster 4500-D Series Service Manual page 326

Testing
Electrical System: Component Testing
The air heater relay is used on models 30893, 30893TE, 30899 and 30899TE to
provide current for the engine air heater used for starting a cold engine. When
necessary, the air heater relay is energized by the engine ECU.
The glow relay is used on models 30885 and 30887 to provide current to the
engine glow plugs when energized by the engine ECU.
If machine is equipped with a operator cab, the cab power relay provides current
to the operator cab electrical components. The cab power relay is energized
when the ignition switch is in the ON or START position.
The TEC 1, TEC 2 and operator cab power (if equipped) relays reside in the
power center behind the operator's seat
glow relays are attached to the air cleaner mount bracket near the engine ECU
(Figure 204).
86
85
g276021
1. Park machine on a level surface, lower cutting decks, stop engine, engage
parking brake and remove key from the ignition switch.
2. To make sure that machine operation does not occur unexpectedly,
disconnect negative (−) cable from battery and then disconnect positive (+)
cable from battery (see
3. Locate relay that is to be tested.
4. Disconnect wire harness connector from relay. Remove relay from mounting
bracket for testing.
5. Using a multimeter, verify that coil resistance between terminals 86 and 85
is approximately 72 ohms.
6. Connect multimeter (ohms setting) leads to relay terminals 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.
7. Disconnect voltage and test leads from the relay terminals.
8. Secure relay to mounting bracket and connect wire harness connector to
relay.
9. Secure all removed components to machine.
10. Connect positive (+) cable to battery and then connect negative (−) cable to
battery (see Battery Service (page
(Figure
87
30
Figure 205
Battery Service (page
6–71)).
Page 6–44
203). The start, air heater and
30
85 86
87
6–71)).
Groundsmaster ® 4500-D/4700-D
19245SL Rev A