Service Manual

Rev. A
Groundsmaster 4500−D/4700−D Page 5 − 45 Electrical System
Hydraulic Oil Temperature Sender
A temperature sender is used as an input for the TEC
controller to identify if the hydraulic oil temperature has
reached an excessive level. The hydraulic oil tempera-
ture sender is attached to the rear axle motor at the rear
of the machine (Fig. 55).
The InfoCenter will display fault code 18 if the hydraulic
oil temperature sender inputs to the TEC controller are
not in the normal range.
Testing
NOTE: Before disconnecting the hydraulic oil temper-
ature sender for testing, the sender and its circuit wiring
should be tested as a TEC electrical input using the In-
foCenter Display (see InfoCenter Display in this
chapter). If input testing verifies that the temperature
sender and circuit wiring are functioning correctly, no
further sender testing is necessary. If, however, input
testing determines that the temperature sender and cir-
cuit wiring are not functioning correctly, proceed with
the following temperature sender testing procedure.
1. Park machine on a level surface, lower cutting
decks, engage parking brake and stop engine. Remove
key from ignition switch.
2. Locate hydraulic oil temperature sender on bottom of
rear axle motor. Disconnect wire harness connector
from sender.
3. Thoroughly clean area around temperature sender
and remove sender from rear axle motor.
4. Put sensing end of sender in a container of oil with
a thermometer and slowly heat the oil (Fig. 56).
CAUTION
Handle the hot oil with extreme care to prevent
personal injury or fire.
NOTE: Prior to taking resistance readings with a digital
multimeter, short the meter test leads together. The me-
ter will display a small resistance value (usually 0.5
ohms or less). This resistance is due to the internal re-
sistance of the meter and test leads. Subtract this value
from from the measured value of the tested component.
5. Check resistance of the sender with a multimeter
(ohms setting) as the oil temperature increases.
A. The meter should indicate from 11.6 to 13.5 kilo
ohms at 68
o
F (20
o
C).
B. The meter should indicate from 2.3 to 2.5 kilo
ohms at 140
o
F (60
o
C).
C. The meter should indicate from 605 to 669 ohms
at 212
o
F (100
o
C).
D. Replace sender if specifications are not met.
6. After allowing the sender to cool, install sender into
axle motor:
A. Install new O−ring on sender and thread sender
into motor port. Torque sender from 9 to 11 ft−lb
(12.3 to 14.9 N−m).
B. Connect wire harness connector to sender.
7. Check and fill hydraulic system to proper level.
Figure 55
1. Rear axle motor 2. Oil temp sender
1
2
FRONT
Figure 56
Electrical
System