Theory Of Operation And Sub-Circuit Schematics; Power Circuit-Theory Of Operation - Textron Jacobsen SLF530 Repair Manual

ELECTRICAL
Theory of Operation and
Sub-Circuit Schematics
Power Circuit—Theory of Operation
Unswitched Power Circuit (Red)
Unswitched power is available from the battery positive
terminal to the starter motor battery terminal, 60-amp
alternator fuse F13 and 175-amp vehicle fuse F14.
Unswitched power is available from 60-amp alternator
fuse (F13) output terminal to the alternator battery
terminal.
Unswitched power is available from the 175-amp vehicle
fuse to the following:
• 15-amp light fuse (F3)
• 10-amp ignition fuse (F7)
• 35-amp RAC2 fuse (F9)
• 35-amp RAC3 fuse (F10)
4
• 50-amp RB1 fuse (F11)
• 50-amp RB2 fuse (F12)
• 30-amp cooling fan fuse (F15) D
• 30-amp starter fuse (F16) D
• 30-amp ECU fuse (F17) G
• 30-amp power fuse (F18) D
• 35-amp glow plug fuse (F19) D
• 10-amp differential lock fuse (F19) G
• Accessory relay (K7) terminal 30
Unswitched power is available from 15-amp fuse (F3)
output terminal to the light relay (K3) terminal 30.
Unswitched power is available from 10-amp fuse (F7)
output terminal to the ignition switch (SW1) terminals 1
and 6.
Unswitched power is available from 35-amp fuse (F9)
output terminal to the RAC2 relay (K5) terminal 30.
Unswitched power is available from 35-amp fuse (F10)
output terminal to the RAC3 relay (K6) terminal 30.
Unswitched power is available from 50-amp fuse (F11)
output terminal to the RB1 stud on the fuse/relay block.
Unswitched power is available from 50-amp fuse (F12)
output terminal to the RB1 stud on the fuse/relay block.
Unswitched power is available from 30-amp fuse (F15)
output terminal to the cooling fan relay (K13) terminal 30.
Unswitched power is available from 30-amp fuse (F16)
output terminal to the starter relay (K10) terminal 30.
Unswitched power is available from 30-amp fuse (F17)
output terminal to the ECU relay (K15) terminals 30 and
86.
Unswitched power is available from 30-amp fuse (F18)
output terminal to the power relay (K12) terminal 30.
4-12
Unswitched power is available from 35-amp fuse (F19)
output terminal to the starter relay (K14) terminal 30.
Unswitched power is available from 10-amp fuse (F19)
output terminal to the differential lock driver (U9) terminal
B.
Switched Power Circuit (Green)
When the key switch (SW1) is turned to the run position,
voltage is provided from key switch terminal 4 to ignition
relay (K1) terminal 86, energizing the relay and to MCU
(U1) terminal 1-02.
With the ignition relay (K1) energized, switched power is
provided from ignition relay terminal 87 to the following
components:
• 10-amp fuse (F1)
• 10-amp fuse (F8)
• 4WD Relay (K5) terminal 30
• Fuel pump (M2)
• Mow Switch (SW2) terminal 2
• Joystick (SW3) terminal 1
• Seat switch (SW4) terminal 1
• Air ride seat switch (SW4A) terminal 3
• Parking brake (SW5) terminal 2
• Light switch (SW6) terminal 2
• Neutral Switch (SW7) terminal 1
• Lift proximity switch (SW8) terminal 1
• Forward proximity switch (SW10) terminal 1
• LDU display (U2) terminal 1-03
• Alternator (U4) terminal I
With switched power provided to the MCU, the MCU will
energize.
Switched power is provided from 10-amp fuse (F1) to the
12 volt accessory outlet (U5)
Switched power is provided from 10-amp fuse (F8) to the
following:
• Air ride seat (M3) terminal 4
• Fan relay (K4) terminal 30
With switched power provided to the fuel pump, the fuel
pump starts to operate.
With switched power provided to the LDU, the LDU
display will energize and will display vehicle status.
Note: For proper operation of the SLF530 mower, the 5
amp fuse (F10) must be removed from the fuse block.
Interlock Circuit (Orange)
The interlock circuit sets the mower in a condition that will
allow the engine to start. The interlock conditions are:
• Mow switch (SW2) in the off position, no voltage
detected at MCU (U1) terminal 4-09
673831-Rev A