Toro ProLine H800 Service Manual page 240

Testing the Relays with 4 Terminals
Electrical System: Testing the Electrical Components
The two (2) reverse fan relays are attached to the battery support plate under the
operator seat (Figure 134). When energized, the reverse fan relays allow the
electrical current to the radiator fan.
The key relay is attached inside the left arm console above the battery
134). When energized, the key relay allow the electrical current to the machine.
1. Park the machine on a level surface, lower the cutting deck, shut off the
engine, set the parking brake, and remove the key from the key switch.
2. To get access to the glow relay, forward relays and reverse relays, remove
the operator seat; refer to
3. To get access to the key relay, remove the left console; refer to
the Body Assembly (page
4. To ensure that the machine operation does not occur unexpectedly,
disconnect the negative (-) cable from the battery and then disconnect the
positive (+) cable from the battery; refer to
5. Locate the relay that is to be tested and disconnect the wire harness
connectors from the relay. Remove the relay from the mounting bracket for
testing.
Note: Before taking small resistance readings with a digital multimeter, short
the multimeter test leads together. The meter displays a small resistance
value (usually 0.5 ohms or less). This resistance is because of the internal
resistance of the multimeter and test leads. Subtract this value from the
measured value of the component that you are testing.
g214499
6. Check the coil resistance between the terminals 85 and 86 with a multimeter
(ohms setting). The resistance should be approximately 72 ohms.
7. Connect the multimeter (ohms setting) leads to relay terminals 30 and 87.
Ground the terminal 85 and apply +12 VDC to terminal 86. The relay should
make and break continuity between the terminals 30 and 87 as +12 VDC is
applied and removed from terminal 86
8. Disconnect the voltage and leads from the relay terminals.
9. Replace the relay if testing determines that the relay is damaged.
Removing the Operator Seat (page
7–6).
Servicing the Battery (page
Figure 135
(Figure
Page 6–40
(Figure
7–17).
Disassembling
135).
ProLine H800
19241SL Rev A
6–46).