Diode Assemblies - Toro Groundsmaster 4300-D Service Manual

Diode Assemblies

Testing the Diode Assembly
Groundsmaster ® 4300-D
16226SL Rev C
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1. End of the diode body
2. Diode assembly
g190805
1. Diode (2 each)
The electrical system of the Groundsmaster 4300-D machine includes 2 identical
diodes. The maximum current allowed through any of the diodes is 6 A. The
diode assemblies can be identified by a black color, diode symbol, and Toro Part
Number on the end of the diode assembly body
into the engine wire harness near the Yanmar engine ECU
the Engine Wire Harness Drawing/Diagram in Appendix A—Foldout Drawings.
A diode assembly (D1) is used for circuit protection from the voltage spikes that
occur when the engine starter solenoid is de-energized.
A diode assembly (D2) is used to protect the engine ECU from reverse polarity in
the EGR relay circuit.
1. Park the machine on a level surface, lower the cutting decks, shut off the
engine, set the parking brake, and remove the key from the key switch.
2. Locate the diode assembly that is to be tested and remove the cable tie
that secures the diode to the wire harness. Unplug the diode from the wire
harness for testing.
Figure 190
3. Male terminal
4. Female terminal
Figure 191
2. Engine ECU
Page 5–83 Electrical System: Testing the Electrical Components
(Figure 190). The 2 diodes plug
(Figure 191); refer to