Traction Neutral Switch; Diode Assemblies - Toro Groundsmaster
4000?D Service Manual

PRELIMINARY – For Toro Distributor and Toro Company use only.

Traction Neutral Switch

The traction neutral switch is closed when the traction
pedal is in the neutral position and opens when the pedal
is depressed in either direction. The switch is located on
the right side of the piston (traction) pump.
Test the switch by disconnecting the wires from the
switch terminals and connecting a continuity tester
across the two switch terminals. With the engine turned
off, slowly push the traction pedal in a forward or reverse
direction while watching the continuity tester. There
should be indications that the traction neutral switch is
opening and closing. Allow the traction pedal to return
to the neutral position. There should be continuity
across the switch terminals when the traction pedal is in
the neutral position.
See Piston Pump Control Assembly in Chapter 4 − Hy-
draulic Systems for disassembly and assembly proce-
dures for the neutral switch.

Diode Assemblies

The Groundsmaster 4000−D electrical system includes
several diode assemblies (Fig. 38) that are used for cir-
cuit protection and circuit logic control. The diodes plug
into the wiring harness at various locations on the ma-
chine.
The diodes D2, D4, D5, D6 and D7 are used for circuit
protection that occur when a hydraulic valve solenoid is
de−energized. Diode D2 is in the Transport/Mow circuit,
D4 is in the left cutting deck circuit, D5 is in the front cut-
ting deck circuit, D6 is in the right cutting deck circuit and
D7 is in the cruise control circuit.
Diode D8 provides a latching circuit to keep the cruise
relay energized.
Diode D9 provides logic for the high temperature warn-
ing system.
Testing
The diodes can be individually tested using a digital
multimeter (diode test or ohms setting) and the table to
the right.
Electrical System
1
1. Piston pump (bottom)
1
1. Diode
2. Male terminal
Multimeter
Red Lead (+)
on Terminal
Female
Male
Page 5 − 26
2
Figure 37
2. Neutral switch
Figure 38
3. Female terminal
Multimeter
Black Lead (−) Continuity
on Terminal
Male YES
Female NO
Groundsmaster 4000−D
2
3