John-deere stx38 User Manual download pdf (Page 140)

4 - 56

3/21/97

CIRCUIT OPERATION AND DIAGNOSIS

ELECTRICAL

PTO AND HEADLIGHTS CIRCUITS

OPERATION

STX38 (SN 210001— ) & STX46

Function:

To provide power to energize the PTO clutch and

headlights (optional).

Operating Conditions:

PTO—

The key switch (S1) must be in the RUN position, the

seat switch must be DEPRESSED (operator ON the

seat), the brake switch must be turned OFF (brake

pedal released), and the PTO switch (S2) must be

ENGAGED.

Headlights—

The key switch (S1) must be in RUN position and the

optional headlight switch (S5) must be pushed ON

(ENGAGED).

Theory of Operation:

PTO—

The PTO circuit uses the ignition circuit to stop the

engine if the operator gets off the seat with the PTO

engaged.

Current flows from the battery (G1) positive terminal to

the key switch (S1) via the starter solenoid (K1)

connection point, fusible link (F1) 201 light orange wire,

and 200 red wire. With the key switch (S1) in the RUN

position, current flows to the PTO switch (S2) via the

400 yellow wire.

The seat switch must be ENGAGED (operator ON the

seat) to prevent a path to ground for the ignition circuit

through the turned OFF (released) brake switch,

allowing the engine to RUN and power the PTO drive

sheave.

When the PTO switch (S2) is moved to the ON position

(ENGAGED), current flows through the PTO switch

(S2) and 750 blue wire to energize the PTO clutch (Y1)

windings. The energized PTO clutch magnet pulls the

PTO clutch brake away from the sheave plate, allowing

the sheave plate to turn with the engine crankshaft.

If the operator gets OFF the seat, the seat switch

creates a path to ground for the ignition circuit and the

engine kills. Once the engine has been killed, the PTO

switch (S2) must be pushed into the OFF position

before the cranking circuit can be engaged to restart

the engine.

Headlights—

Current flows from the battery (G1) positive terminal to

the key switch (S1) via the starter solenoid (K1)

connection point, fusible link (F1) 201 light orange wire,

and 200 red wire. With the key switch (S1) in the RUN

position, current flows to the PTO switch (S2) via the

400 yellow wire. At this tie point, current flows through

the 450 yellow/white to the headlights switch (S5).

When the headlights switch (S5) is pushed ON

(ENGAGED), current flows through the 451 yellow/

white wire through the headlights kit harness yellow

wire into the two red wire to the twin headlights, then to

engine ground (W2) via the black wires of the

headlights kit harness and the tractor harness 120

black wire.

The headlights are turned OFF by turning off the

headlights switch (S5) or the key switch (S1).

1 ... 139 140 141 ... 314

Comments to this Manuals

No comments

John-deere stx38 User Manual Page 140

Comments to this Manuals

Related products and manuals for Special machinery John-deere stx38