Diode Circuit Board - Toro Groundsmaster
4000?D Service Manual

PRELIMINARY – For Toro Distributor and Toro Company use only.

Diode Circuit Board

The circuit board contains four diodes (Fig. 39) and is lo-
cated under the console housing. The diodes are used
for circuit protection from inductive voltage spikes that
occur when a hydraulic valve solenoid is de−energized.
Diode D1 is in the left cutting deck circuit, D2 is in the
Transport/Mow circuit, D3 is in the front cutting deck cir-
cuit and D4 is in the right cutting deck circuit.
Testing
The diodes can be individually tested using a digital
multimeter (ohms setting) and the table to the right. If
any of the diodes are damaged, the diode circuit board
must be replaced.
Groundsmaster 4000−D
CIRCUIT BOARD
Red Lead (+)
on
Terminal
H
A
G
B
F
C
E
D
Page 5 − 27
DIODE DIAGRAM
Figure 39
Black Lead (−)
on Continuity
Terminal
A YES
H NO
B YES
G NO
C YES
F NO
D YES
E NO
Electrical System
H
G
F
E
D
C
B
A