Jacobsen AR3, Technical/Repair Manual

Page: 86 / 342

ELECTRICAL
4181384 First Edition 4-29
4
Start Circuit—Theory of Operation
Power Circuit
Unswitched power is available to key switch terminal 30
and 40-amp fuse F12. When the key switch is turned to
the run position, current flows from the AC terminal of the
key switch through 10-amp fuse F10 to control module
terminals 3 and 8, powering up the module. With the
control module powered up, pin 2 of the control module
now provides 5 volts to the seat switch and park brake
switch.
Start Relay Circuit
Start relay K1 must be energized before current can flow
from the key switch to the starter motor solenoid. To
energize the start relay the following must occur:
• Operator on the seat
• Park brake switch in the locked position
• Drive pedal in the neutral position
• Mow switch in the off position
When the operator is on the seat, the seat switch
contacts close. With the seat switch contacts closed,
voltage is provided to control module 5V seat switch
input, activating the input.
When park brake switch is in the locked position and the
neutral switch is in the neutral position, voltage is
provided to the control module 5V park brake switch
input, activating the input.
When the mow switch is in the off position, the control
module 5V mow switch input is de-activated. (See “Mow
Circuit—Theory of Operation” on page 4-38.).
With the control module's 5V seat and 5V park brake
switch inputs activated and the 5V mow switch input
de-activated, the control module's 12V start relay output
terminal provides voltage to start relay terminal 1,
energizing the relay.