Diode Circuit Board - Toro Reelmaster 2300-D Service Manual

Diode Circuit Board

The circuit board contains four diodes. Three diodes are
used for circuit protection from inductive voltage spikes.
The remaining diode is used as part of the safety circuit
logic.
Diode D1
This diode allows a current path through the traction in-
terlock switch when the seat interlock switch is open.
The engine can be started and run with no operator in
the seat when the traction pedal is in the neutral position.
Possible indications of diode failure may be: The engine
will crank but not start with the operator out of the seat
with the traction pedal in neutral, the engine will shut
down when the operator leaves the seat with the cutting
unit switch in the off position and the traction pedal in
neutral, or the engine cranks with the traction pedal not
in neutral.
Diode D2
This diode protects the cutting unit switch, interlock
switch, and indicator light from inductive voltage spikes
caused by the cutting unit solenoid valve.
Possible indications of diode failure may be the failure
or repeated failure of those components above
associated with the cutting unit solenoid valve circuit.
Diode D3
This diode protects the ignition switch and starter relay
contacts from induction voltage spikes caused by the
starter solenoid.
Possible indications of diode failure may be the failure
or repeated failure of those components above
associated with the starter solenoid circuit.
Diode D4
This diode protects the seat interlock switch and cutting
unit switch from induction voltage spikes caused by the
fuel valve solenoid.
Possible indications of diode failure may be the failure
or repeated failure seat interlock switch.
Testing
The diodes can be individually tested using a digital
multimeter (ohms setting) and the table to the right.
Electrical System
Red Lead (+)
on
Terminal
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A
G
B
F
C
E
D
Page 5 – 22
H
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C
B
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DIODE
DIAGRAM
Figure 15
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DIODE
CIRCUIT BOARD
Figure 16
Black Lead (–)
on Continuity
Terminal
A
H
B
G
C
F
D
E
Reelmaster 2300–D/2600–D
YES
NO
YES
NO
YES
NO
YES
NO