Cooling Fan Switch - Toro Groundsmaster 4000-D Service Manual

Cooling Fan Switch

The cooling fan switch is used to control the operation
of the hydraulic cooling fan and is located on the control
console (Fig. 21). This switch has three (3) positions:
Reverse, Auto and Forward.
When the cooling fan switch is in the normal Auto posi-
tion, cooling fan operation is controlled by the
TEC--5002 controller. In this switch position, if either en-
gine coolant or hydraulic oil temperature is excessive,
the fan will stop and then reverse direction to allow auto-
matic debris cleaning of the radiator, oil cooler and rear
intake screen. The controller determines the length of
time that the fan should be run in reverse before fan rota-
tion is returned to the forward direction.
If the operator depresses the cooling fan switch to the
Reverse position, a fan reverse cycle that is controlled
by the TEC--5002 controller is initiated. The switch auto-
matically returns to the Auto position and fan operation
returns to the forward direction after the reverse cycle is
completed.
If the cooling fan switch is placed in the Forward posi-
tion, the engine cooling fan will run only in the forward
direction.
Testing
The switch terminals are shown in Figure 22. The circuit-
ry of the switch is shown in the chart below. With the use
of a multimeter (ohms setting), the switch functions may
be tested to determine whether continuity exists be-
tween the various terminals for each position. Verify
continuity between switch terminals.
SWITCH NORMAL
POSITION CIRCUITS
NORMAL
REVERSE
FORWARD
Electrical System
OTHER
CIRCUITS
2 + 3 NONE
2 + 3 5 + 6
NONE NONE
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1. Control console
BACK OF COOLING FAN SWITCH
Page 5 - - 14
Figure 21
2. Cooling fan switch
4 5 6
1 2 3
Figure 22
Groundsmaster 4000--D
2