Toro 3000D manual Diode Circuit Boards

Diode Circuit Boards

Each circuit board contains four diodes. The diodes are used for circuit protection from inductive voltage spikes, battery charging indication, and for safety circuit logic. Diodes D4 and D8 are not used.

On the GM 3000 wiring diagram, the diode circuit cards a designated P3 and P5. On the GM 3000–D wiring dia- grams, the diode circuit cards are designated P7 and P5.

Diode D1

Directs current flow from the deck capacitor to the deck relay when the seat relay is de–energized to provide a 1 second delay.

Diode D2

Provides current flow logic for the charging circuit light.

Diode D3

Prevents a negative spike from damaging the PTO switch by allowing a ground path for the PTO relay and PTO coil when they de–energize.

Diode D4

This component is not used.

Diode D5

Prevents a negative spike from damaging the Lift/Xbal switch by allowing a ground path for the Lift/Xbal sole­ noid (SV1) when it de–energizes.

Diode D6

Prevents a negative spike from damaging the Cruise switch by allowing a ground path for the Cruise relay and Cruise coil when they de–energize.

Diode D7

Prevents a negative spike from damaging the Transport switch by allowing a ground path for the Transport relay and Transport coil when they de–energize.

Diode D8

Prevents a negative spike from damaging the Float/ Hold switch by allowing a ground path for the Float/Hold solenoid (SV2) when it de–energizes.

Testing

The diodes can be individually tested using a digital multimeter (ohms setting) and the table to the right.

D2

	D6
	D4
	D8
	D3
	D7
	D1
	D5
A B C D	DIODE	E F G H
	DIAGRAM
	Figure 6
P3 or P7	P5

DIODE

CIRCUIT BOARDS

Figure 7

Red Lead (+)	Black Lead (–)	Continuity
on Terminal	on Terminal
H	A	YES
A	H	NO
G	B	YES
B	G	NO
F	C	YES
C	F	NO
E	D	YES
D	E	NO

DIODE CIRCUIT BOARD

Figure 8

Electrical System Page 6 – 10 Groundsmaster 3000/3000–D