Diode Assemblies - Toro Workman HDX Auto Service Manual

Diode Assemblies

The protection diode assembly is used for starting circuit
protection from voltage spikes that occur when the start-
er solenoid is de−energized. This diode plugs into the
rear wire harness under the right side of the bed near the
engine.
Four (4) diode assemblies are used for circuit logic in the
transmission gear selection system. The park, reverse
low and high diode assemblies plug into the front wire
harness behind the dash.
If a vehicle is equipped with the optional light kit that in-
cludes flashers, two (2) additional diode assemblies are
used for flasher circuit logic. These diodes plug into the
front wire harness behind the dash. The LH diode
(GREEN harness wire) and RH diode (BROWN harness
wire) can be identified by the color of the wire harness
conductor at the harness connector for the diode.
The diode assemblies can be identified by a black color
and a diode symbol on the end of the diode assembly
body (Fig. 28). Refer to the appropriate wire harness
drawings in Chapter 9 − Electrical Drawings for addition-
al information on diode assembly location.
Testing
1. Park vehicle on a level surface, engage parking
brake. Stop the engine and remove key from ignition
switch. Allow engine to cool.
2. Locate diode assembly that is to be tested:
A. For protection diode testing, raise and support the
cargo bed. Make sure engine is off and key is re-
moved from switch after raising bed. Locate protec-
tion diode in rear wire harness.
B. For other diodes, remove hood from machine to
access front wire harness behind the dash (see Hood
in the Service and Repairs section of Chapter 5 −
Chassis).
3. Remove cable tie that secures diode to wire harness.
Unplug the diode from the wire harness for testing.
Electrical System
4. A diode assembly can be tested using a digital multi-
meter (diode test or ohms setting) and the table below.
Multimeter
Red Lead (+)
on Terminal
Female
Male
5. If testing determines that a diode assembly is faulty,
replace diode assembly.
6. After diode testing is complete, make sure that diode
assembly is fully installed into wire harness connector
and secured to harness with cable tie.
7. If cargo bed was raised, remove bed support from
bed lift cylinder and lower bed. If hood was removed, in-
stall hood to machine.
4
1. Diode assembly
2. Male terminal
Page 6 − 22
Multimeter
Black Lead (−) Continuity
on Terminal
Male
Female
1
Figure 28
3. Female terminal
4. End of diode body
Workman HDX Auto
YES
NO
2
3