Ransomes 62287, 62288, 62289, 62302, 62303, 62304, 62305, 62306 User manual

4

4247530-Rev A 4-1

Chapter 4

Electrical

Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

Test and Adjustment Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

Repair Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

Theory and Diagnostic Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Electrical Component Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Electrical Schematic Component Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7

Electrical Schematic—Diesel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8

Electrical Schematic—Gasoline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10

Theory of Operation and Sub-Circuit Schematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12

Power Circuit Diesel—Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12

Power Circuit Gasoline—Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13

Glow Plug Circuit—Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14

Glow Plug Circuit Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14

Start Circuit—Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-15

Start Circuit Schematic—Diesel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-16

Start Circuit Schematic—Gasoline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-17

Charging Circuit—Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18

Charging Circuit Schematic—Diesel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-19

Charging Circuit Schematic—Gasoline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-20

Run Circuit Diesel—Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-21

Run Circuit Schematic Diesel—On Seat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-22

Run Circuit Schematic Diesel—Off Seat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-23

Run Circuit Gasoline—Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-24

Run Circuit Schematic Gasoline—On Seat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-25

Run Circuit Schematic Gasoline—Off Seat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-26

Backlap Circuit—Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-27

Backlap Circuit Schematic—Diesel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-28

Backlap Circuit Schematic—Gasoline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-29

Instrumentation Circuit—Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-30

Instrumentation Circuit Schematic—Diesel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-31

Instrumentation Circuit Schematic—Gasoline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-32

Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-33

Glow Plug Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-33

Start Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-33

Charging Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-34

Run Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-34

Backlap Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-34

Instrumentation Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-35

4-2 4247530-Rev A

ELECTRICAL

4

Component Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-37

Electrical System and Component Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-37

Fuse Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-38

Engine Stop Relay Test (Gasoline) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-38

Time Delay Relay Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-39

Micro Switch Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-39

Glow Plug Switch Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-40

Key Switch Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-40

Backlap Lockout Switch Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-41

Seat Switch Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-41

Start Solenoid Test (Diesel) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-42

Voltage Regulator Test (Diesel) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-42

Fuel Shutoff Solenoid Test (Diesel) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-43

Carb Solenoid Test (Gasoline) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-44

Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-45

Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-45

Alternator (Diesel) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-45

Starter Motor (Diesel) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-46

Starter Motor (Gasoline) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-46

Instrument Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-47

Key Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-48

Micro Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-48

Glow Plug Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-50

Backlap Lockout Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-51

Warning Lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-51

Fuse and Fuse Holder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-52

Engine Stop Relay (Gasoline) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-53

Time Delay Relay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-54

Start Solenoid (Diesel) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-54

Voltage Regulator (Diesel) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-55

Voltage Regulator (Gasoline) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-55

Gauges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-56

Hour Meter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-56

Fuel Shutoff Solenoid (Diesel) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-57

Engine Oil Pressure Switch (Diesel) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-57

Engine Oil Pressure Switch (Gasoline) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-58

Engine Temperature Sensor (Diesel) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-58

ELECTRICAL

4247530-Rev A 4-3

4

Specifications

Test and Adjustment Specifications

Repair Specifications

Specification

Resistance Across Fuel Shutoff Pull-In Coil at 68° F ohm 0.5 ± 10%

Resistance Across Fuel Shutoff Hold-In Coil at 68° F

ohms 13.5 ± 10%

Resistance Across Carb Solenoid Coil at 68° F

ohms 40 ± 10%

Specification

Starter Mounting Screw Torque

(Diesel)

lb-ft (N·m) 17–21 (23–28)

4-4 4247530-Rev A

ELECTRICAL

4

Theory and Diagnostic

Information

Electrical Component Symbols

The following symbols are used in the electrical

schematics to represent various electrical components.

Switches

1

1 The sample switch symbols shown are just a few of the many switch configurations. Switches are

designated by the number of “poles” (circuits controlled) and “throws” (actuator positions). Unless otherwise

specified, switches are shown in the “Normally Open” (N.O.) position.

Single Pole, Single Throw

(SPST)

Double Pole, Single Throw

(DPST)

Single Pole, Double Throw

(SPDT)

Double Pole, Double Throw

(DPDT)

Proximity Switch

Switching Devices

Temperature Switch Pressure Switch

Relay

Circuit Protection Devices

Fuse Circuit Breaker

N.O.

Blk Wht

(+)

t˚

P

87 87A85

86 30

ELECTRICAL

4247530-Rev A 4-5

4

Motors and Generating Devices

Electric Motors (may also

include “AC” or “DC.”)

Stator

Alternator

Actuating Devices

Solenoid Valve PTO Clutch

Engine-Related Devices

Ignition Coil Spark Plug

Regulator Fuel Shutoff Solenoid

Lights

Single-Element Light Dual-Element Light

M

G

U

3

U

Hold-In

Coil

Pull-In

Coil

4-6 4247530-Rev A

ELECTRICAL

4

Miscellaneous Symbols

Enclosure

(cabinet, housing, etc.)

Wires (crossing but not

connected)

Ground (to earth) Wiring Connections

Ground (to chassis) Coil

Direct Current (DC)

(as shown on an oscilloscope)

Battery

Alternating Current (AC)

(as shown on an oscilloscope)

Diode

Resistor Pin and Socket Connector

(+)

(-)

ELECTRICAL

4247530-Rev A 4-7

4

Electrical Schematic Component Identification

Electrical components shown in the main schematic are identified with an alphanumeric callout. All electrical

components shown in the electrical schematic are listed below.

• B1—Engine Oil Pressure Switch (See Figures 4-2

and 4-4.)

• B2—Engine Temperature Sensor (See Figure 4-2.)

• E1—Park Brake Light (See Figures 4-2 and 4-4.)

• E2—Engine Oil Pressure Light (See Figures 4-2 and

4-4.)

• F1—30A Fuse (Diesel) (See Figure 4-1.)

• F2—30A Fuse (Diesel) (See Figure 4-1.)\

• F3—6A Fuse (See Figures 4-1 and 4-3.)

• F4—20A Fuse (Gasoline) (See Figure 4-3.)

• G1—12V Battery (See Figures 4-1 and 4-3.)

• G2—Alternator (See Figure 4-1.)

• G3—Stator (See Figure 4-3.)

• H1—Volt Meter (See Figures 4-2 and 4-4.)

• H2—Engine Temperature Gauge (See Figure 4-2.)

• H3—Hour Meter (See Figures 4-2 and 4-4.)

• J1—Optional Light Connector (See Figures 4-1 and

4-3.)

• K1—Start Solenoid (Diesel) (See Figure 4-1.)

• K2—Time Delay Relay (Diesel) (See Figure 4-2.)

• K2—Engine Stop Relay (Gasoline) (See Figure 4-3.)

• M1—Starter Motor (See Figures 4-1 and 4-3.)

• N1—Voltage Regulator (See Figures 4-1 and 4-3.)

• R1—Glow Plugs (See Figure 4-1.)

• S1—Key Switch (See Figures 4-1 and 4-3.)

• S2—Glow Plug Switch (See Figure 4-1.))

• S3—Seat Switch (See Figures 4-2 and 4-4.)

• S4—Backlap Lockout Switch (See Figures 4-2 and

4-4.)

• S5—Traction Switch (See Figures 4-2 and 4-4.)

• S6—Brake Switch (See Figures 4-2 and 4-4.)

• S7—Mow Switch (See Figures 4-2 and 4-4.)

• S8—Backlap Switch (See Figures 4-2 and 4-4.)

• S9—Park Brake Light Switch (See Figures 4-2 and

4-4.)

• Y1—Fuel Shutoff Solenoid (Diesel) (See Figure 4-1.)

• Y2—Carb Solenoid (Gasoline) (See Figure 4-3.)

4-8 4247530-Rev A

ELECTRICAL

4

Electrical Schematic—Diesel

See Figures 4-1 and 4-2.

Figure 4-1

Wht

Grn

Pur

Gry

Pur

Red

Red Red

Red

Wht

Blk

Red

M1

Starter

Motor

Grn

R1

Glow

Plugs

M

S1

Key

Switch

G1

12V

Battery

Gry

BrnBrn

Brn

Org

Blk

Org

Blu

Org

Red

BluBlu

Blu Blu

Yel Yel

Off

Run

Start

B

X

I

S

A

Y

(+)

(-)

Wht

Y1

Fuel

Shutoff

Solenoid

Red

Pur

Pnk

Pnk Pnk

Pur

Blk

Wht

K1

Start

Solenoid

Grn

On

Off

S2

Glow

Plug

Switch

WhtWhtWht

F3

6A

Fuse

F2

30A

Fuse

AC

AC B+

G

G2

Alternator

B+

N1

Voltage

Regulator

J1

Optional

Light

Connector

Unswitched Power Circuit

Switched Power Circuit

Interlock Circuit

Ground Circuit

Blk

8630

8587

Red

F1

30A

Fuse

Hold-InPull-In

Blk

TN3337A

ELECTRICAL

4247530-Rev A 4-9

4

Electrical Schematic—Diesel

Continued

Figure 4-2

Blu

Yel Yel

Yel

YelYel

Yel

(B)

(L) (G)

(S)

Yel

Brn Brn

Brn

Gry

Gry Gry Gry Gry Gry

Gry

Gry Gry

Gry

Gry Pur

PurGry

GryGry

Gry

Blk

Pnk

Yel Yel

On

Off

S3

Seat

Switch

S9

Park

Brake

Light

Switch

On

Off

Blu

B

L

G

M

Mow

Backlap

S4

Backlap

Lockout

Switch

K2

Time

Delay

Relay

WhtWht

Blk

Output Gnd

Enable+12V

1 Sec.

Off Delay

E2

Engine

Oil

Pressure

Light

E1

Park

Brake

Light

Blk

B1

Engine

Oil

Pressure

Switch

P

Blu

+12V

Gnd

H3

Hour

Meter

Blk

B2

Engine

Temperature

Sensor

Blk

+12V

SignalGnd

H2

Engine

Temperature

Gauge

Blk

+12V

Gnd

H1

Volt

Meter

Grn

Pnk

Locked

Released

S6

Brake

Switch

Pnk

Neutral

Engaged

S5

Traction

Switch

Neutral/

Reverse

Forward

S7

Mow

Switch

Pnk

Neutral/

Forward

Reverse

S8

Backlap

Switch

Pnk Blu

TN3338

4-10 4247530-Rev A

ELECTRICAL

4

Electrical Schematic—Gasoline

See Figures 4-3 and 4-4.

Figure 4-3

Pur

Red

Pur

BrnBrn

Brn

Blk

Red

Pnk/Wht

Pnk/Wht Pnk/Wht

Yel Yel

Red

Org

Org Org

YelYel

F3

6A

Fuse

J1

Optional

Light

Connector

Ignition

Module

Ignition

Module

Wht

Blk Pur

Blu

Blk

K2

Engine

Stop

Relay

Y2

Carb

Solenoid

8787A 85

8630

S1

Key

Switch

Off

Run

Start

B

X

I

S

A

Y

Unswitched Power Circuit

Switched Power Circuit

Interlock Circuit

Ground Circuit

Red

Blk

G1

12V

Battery

Red

(+)

(-)

Pur

Red

Pur

F4

20A

Fuse

AC

G

G3

Stator

Output (+)

N1

Voltage

Regulator

Grn

M1

Starter

Motor

M

TN3339

ELECTRICAL

4247530-Rev A 4-11

4

Electrical Schematic—Gasoline

Continued

Figure 4-4

Pnk/Wht

Yel

YelYel

Brn Brn

Brn

Pur

Pur Pur Pur Pur Pur

Pur

Pur Pur

Gry Pur

PurPur

Pur

Blk

Org

Yel Yel

On

Off

S3

Seat

Switch

S9

Park

Brake

Light

Switch

On

Off

Pnk/Wht

B

L

G

M

Mow

Backlap

S4

Backlap

Lockout

Switch

Yel

E2

Engine

Oil

Pressure

Light

E1

Park

Brake

Light

Blk

B1

Engine

Oil

Pressure

Switch

P

Blu/

Wht

Blu/

Wht

+12V

Gnd

H3

Hour

Meter

Blk

+12V

Gnd

H1

Volt

Meter

Unswitched Power Circuit

Switched Power Circuit

Interlock Circuit

Ground Circuit

Org

Locked

Released

S6

Brake

Switch

Pnk

Neutral

Engaged

S5

Traction

Switch

Neutral/

Reverse

Forward

S7

Mow

Switch

Pnk

Neutral/

Forward

Reverse

S8

Backlap

Switch

Pnk Blu

TN3340

4-12 4247530-Rev A

ELECTRICAL

4

Theory of Operation and

Sub-Circuit Schematics

Power Circuit Diesel—Theory of

Operation

Reference electrical schematic. See Figures 4-1 and 4-2.

Unswitched Power Circuit

Unswitched power is provided from the battery positive

terminal to the starter motor battery terminal and then

from the starter motor battery terminal to the start

solenoid terminal 30. Start solenoid terminal 30 provides

unswitched power to the key switch terminal X. Junction

at key switch terminal X provides unswitched power to 6A

fuse F3. Unswitched power is provided from 6A fuse F3

to the traction and backlap lockout switches.

The starter motor battery terminal also provides

unswitched power through 30A fuse F1 to the glow plug

switch.

Interlock Circuit

The interlock circuit provides voltage to the key switch.

The following must occur before the key switch is

provided with voltage:

• Traction switch in the neutral position

• Brake switch in the locked position

• Mow switch in the neutral position

• Backlap switch in the neutral position

With the traction switch in the neutral position, voltage is

provided from the traction switch to the brake switch.

With the brake switch in the locked position, voltage is

provided from the brake switch to the mow switch.

With the mow switch in the neutral position, voltage is

provided from the mow switch to the backlap switch.

With the backlap switch in the neutral position, voltage is

provided from the backlap switch to the key switch

terminal B.

Switched Power Circuit

When the key switch is turned to the run position, voltage

is provided from key switch terminal I to the fuel shutoff

solenoid hold-in coil. Key switch terminal I also provides

voltage to the following:

• Park brake light switch

• Engine oil pressure light

• Volt meter

• Engine temperature gauge

• Hour meter

With voltage provided to the hour meter, the hour meter

starts logging hours.

With the key switch in the run position and the engine

operating, the voltage regulator provides voltage to key

switch terminal Y through 30A fuse F2. Key switch

terminal X provides voltage to start solenoid terminal 30

and then to the starter motor battery terminal. Voltage is

provided from the starter motor battery terminal to the

battery positive terminal. (See “Charging Circuit—Theory

of Operation” on page 4-18.)

Key switch terminal Y also provides voltage to the

optional light connector.

ELECTRICAL

4247530-Rev A 4-13

4

Power Circuit Gasoline—Theory of

Operation

Reference electrical schematic. See Figures 4-3 through

4-4.

Unswitched Power Circuit (Gasoline)

Unswitched power is provided from the battery positive

terminal to the starter motor battery terminal and then

from the starter motor battery terminal to key switch

terminal X. The starter motor battery terminal provides

unswitched power to 6A fuse F3. Unswitched power is

provided from 6A fuse F3 to the traction and seat

switches.

When the engine is operating, the voltage regulator

provides voltage to the starter motor battery terminal

through 20A fuse F4 and then to the battery. (See

“Charging Circuit—Theory of Operation” on page 4-18.)

Interlock Circuit

The interlock circuit provides voltage to the key switch.

The following must occur before the key switch is

provided with voltage:

• Traction switch in the neutral position

• Brake switch in the locked position

• Mow switch in the neutral position

• Backlap switch in the neutral position

With the traction switch in the neutral position, voltage is

provided from the traction switch to the brake switch.

With the brake switch in the locked position, voltage is

provided from the brake switch to the mow switch.

With the mow switch in the neutral position, voltage is

provided from the mow switch to the backlap switch.

With the backlap switch in the neutral position, voltage is

provided from the backlap switch to key switch terminal

B.

Switched Power Circuit

When the key switch is turned to the run position, voltage

is provided from key switch terminal I to the carb solenoid

and engine stop relay terminal 86. Key switch terminal I

also provides voltage to the following:

• Park brake light switch

• Engine oil pressure light

• Volt meter

• Hour meter

With voltage provided to the hour meter, the hour meter

starts logging hours.

With the key switch in the run position, key switch

terminal Y provides voltage to the optional light

connector.

4-14 4247530-Rev A

ELECTRICAL

4

Glow Plug Circuit—Theory of

Operation

Unswitched Power Circuit

The starter motor battery terminal provides unswitched

power through 30A fuse F1 to the glow plug switch.

Glow Plug Circuit

When the glow plug switch is held in the on position,

voltage is provided to the glow plugs, heating the glow

plugs.

Glow Plug Circuit Schematic

See Figure 4-5.

Figure 4-5

Blk

Red Red

Red

M1

Starter

Motor

Grn

R1

Glow

Plugs

M

G1

12V

Battery

Red

(+)

(-)

Grn

On

Off

S2

Glow

Plug

Switch

Unswitched Power Circuit

Glow Plug Circuit

Ground Circuit

Red

F1

30A

Fuse

TN3359

ELECTRICAL

4247530-Rev A 4-15

4

Start Circuit—Theory of Operation

Interlock Circuit

The interlock circuit provides voltage to the key switch.

The following must occur before the key switch is

provided with voltage:

• Traction switch in the neutral position

• Brake switch in the locked position

• Mow switch in the neutral position

• Backlap switch in the neutral position

With the traction switch in the neutral position, voltage is

provided from the traction switch to the brake switch.

With the brake switch in the locked position, voltage is

provided from the brake switch to the mow switch.

With the mow switch in the neutral position, voltage is

provided from the mow switch to the backlap switch.

With the backlap switch in the neutral position, voltage is

provided from the backlap switch to the key switch

terminal B.

Start Circuit (Diesel)

When the key switch is turned to the run position, voltage

is provided from key switch terminal I to the fuel shutoff

hold-in coil.

When the key switch is turned to the start position,

voltage is provided from key switch terminal S to the start

solenoid, energizing the solenoid. With the start solenoid

energized, voltage is provided from start solenoid

terminal 87 to the starter motor solenoid, energizing the

solenoid. With the starter motor solenoid energized,

voltage is provided from the starter motor solenoid

contacts to the starter motor, engaging the motor.

The starter solenoid contacts also provide voltage to the

fuel shutoff solenoid pull-in coil, energizing the coil. With

the pull-in coil energized, the solenoid plunger retracts.

The hold-in coil keeps the solenoid plunger in the

retracted position until it is de-energized. With the

solenoid plunger retracted, fuel is allowed to flow, and as

the starter motor cranks the engine, the engine starts

operating.

Start Circuit (Gasoline)

When the key switch is in the run position, key switch

terminal I provides voltage to the carb solenoid,

energizing the solenoid. With the solenoid energized, the

carb solenoid plunger retracts, allowing fuel to flow.

With the key switch in the run position, key switch

terminal I also provides voltage to engine stop relay

terminal 86, energizing the relay. With the relay

energized, the engine stop relay un-grounds the ignition

modules, allowing the modules to produce spark when

the engine is turning.

When the key switch is turned to the start position,

voltage is provided from key switch terminal S to the

starter motor solenoid, energizing the solenoid. With the

starter motor solenoid energized, voltage is provided

from the starter motor solenoid contacts to the starter

motor, engaging the motor.

4-16 4247530-Rev A

ELECTRICAL

4

Start Circuit Schematic—Diesel

See Figure 4-6.

Figure 4-6

Wht

Grn

Pur Pur

Red

Wht

Blk

Red

M1

Starter

Motor

M

S1

Key

Switch

G1

12V

Battery

Red

BluBlu

Blu Blu

Off

Run

Start

B

X

I

S

A

Y

(+)

(-)

Red

Pur

Pnk

Pnk Pnk

Wht

K1

Start

Solenoid

F3

6A

Fuse

Pnk

Locked

Released

S6

Brake

Switch

Pnk

Neutral

Engaged

S5

Traction

Switch

Pnk

Neutral/

Reverse

Forward

S7

Mow

Switch

Pnk

Neutral/

Forward

Reverse

S8

Backlap

Switch

Pnk Blu

Unswitched Power Circuit

Switched Power Circuit

Interlock Circuit

Ground Circuit

Start Circuit

Fuel Pull-In Circuit

Blk

8630

8587

Wht

Y1

Fuel

Shutoff

Solenoid

Pur

Hold-InPull-In

Blk

TN3363

ELECTRICAL

4247530-Rev A 4-17

4

Start Circuit Schematic—Gasoline

See Figure 4-7.

Figure 4-7

Pur

Pur Pur

Pnk/Wht

Pnk/Wht Pnk/Wht

Org

Red

Org

F3

6A

Fuse

Ignition

Module

Ignition

Module

Wht

Blk Pur

Blu

Blk

K2

Engine

Stop

Relay

Y2

Carb

Solenoid

8787A 85

8630

S1

Key

Switch

Off

Run

Start

B

X

I

S

A

Y

Org

Locked

Released

S6

Brake

Switch

Pnk

Neutral

Engaged

S5

Traction

Switch

Pnk

Neutral/

Reverse

Forward

S7

Mow

Switch

Pnk

Neutral/

Forward

Reverse

S8

Backlap

Switch

Pnk Pnk/Wht

Unswitched Power Circuit

Switched Power Circuit

Start Circuit

Interlock Circuit

Ground Circuit

Red

Blk

G1

12V

Battery

Red

(+)

(-)

M1

Starter

Motor

M

TN3364

4-18 4247530-Rev A

ELECTRICAL

4

Charging Circuit—Theory of

Operation

Charging Circuit (Diesel)

The charging circuit is an alternator with a external

voltage regulator design. As the alternator turns, the

alternator produces AC voltage. The AC voltage is

rectified by the voltage regulator, and DC voltage is

produced. The DC voltage is used to charge the battery.

When the battery voltage is low, the voltage regulator

supplies regulated voltage to charge the battery. When

the battery is fully charged, the regulator stops providing

regulated voltage to the battery.

With the key switch in the run position, the voltage

regulator provides voltage to key switch terminal Y

through 30A fuse F2. Key switch terminal X provides

voltage to start solenoid terminal 30 and then to the

starter motor battery terminal. Voltage is provided from

the starter motor battery terminal to the battery positive

terminal.

Charging Circuit (Gasoline)

The charging circuit is a permanent magnet and stator

design. As the flywheel turns, the magnets pass the

stator coils, producing AC voltage. The AC voltage is

rectified by the voltage regulator, and DC voltage is

produced. The DC voltage is used to charge the battery.

When the battery voltage is low, the voltage regulator

supplies regulated voltage to charge the battery. When

the battery is fully charged, the regulator stops providing

regulated voltage to the battery.

The voltage regulator provides voltage to the starter

motor battery terminal through 20A fuse F4 and then to

the battery.

ELECTRICAL

4247530-Rev A 4-19

4

Charging Circuit Schematic—Diesel

See Figure 4-8.

Figure 4-8

Red

Red Red

Blk

Red

M1

Starter

Motor

M

S1

Key

Switch

G1

12V

Battery

Org Org Org

Org

Blu

Org

Red

Off

Run

Start

B

X

I

S

A

Y

(+)

(-)

Red

Blk

Wht

K1

Start

Solenoid

F2

30A

Fuse

AC

AC B+

G

G2

Alternator

B+

N1

Voltage

Regulator

Unswitched Power Circuit

Charging Circuit

Ground Circuit

TN3357

4-20 4247530-Rev A

ELECTRICAL

4

Charging Circuit Schematic—Gasoline

See Figure 4-9.

Figure 4-9

Unswitched Power Circuit

Charging Circuit

Ground Circuit

Red

Blk

G1

12V

Battery

Red

(+)

(-)

Pur Pur

Red

Pur

F4

20A

Fuse

AC

G

G3

Stator

Output (+)

N1

Voltage

Regulator

M1

Starter

Motor

M

TN3358

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Ransomes 62287, 62288, 62289, 62302, 62303, 62304, 62305, 62306 User manual

Ransomes 62287, 62288, 62289, 62302, 62303, 62304, 62305, 62306 User manual

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