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.
D2
D4
D3
D1
H
G
F
E
D
C
B
A
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.
DIODE
DIAGRAM
Figure 15
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DIODE
CIRCUIT BOARD
Figure 16
Red Lead (+) | Black Lead (±) |
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on | on | Continuity |
Terminal | Terminal |
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H | A | YES |
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A | H | NO |
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G | B | YES |
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B | G | NO |
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F | C | YES |
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C | F | NO |
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E | D | YES |
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D | E | NO |
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Electrical System | Page 5 ± 22 | Reelmaster 2300±D/2600±D |
