Engine Shut-Down Circuits - Cub Cadet 2000 Series Professional Shop Manual

2000 Series Tractors

Engine shut-down circuits

Engine shutdown circuits stop the engine by disabling
the ignition and removes power from the afterfire solenoid.
Key switch shut-down: See Figure 7.22.
The key switch turned to OFF connects the M (Mag-
neto) terminal and A1 to G (Ground).
• Grounding the magneto primary windings pre-
vents the magneto from developing the mag-
netic field that it collapses to generate a spark.
This disables the ignition.
• The A1 terminal is de-energized.
NOTE: On older electrical system, prior to 2008,
the afterfire solenoid was powered by the
alternator. In order to turn off the afterfire
solenoid, the A1 terminal was shorted to
ground inside the key switch. This drains the
current from the alternator, de-energizing the
solenoid. That function was left in place so
that the same key switch can be used, but it
is not needed. The 2000 series tractors pow-
ers the solenoid through the A1 terminal of
the key switch and not the alternator.
Seat switch and brake switch: See Figure 7.23.
The seat switch and brake switch work in series to
ground the magneto primary windings if the brake is
released while the seat is vacant.
1. The magneto (yellow wire) is connected to the N.C.
terminal of the brake switch.
1a. When the park brake is applied, the plunger of
the park brake switch is depressed, opening
the N.C. (Normally Closed) contacts within the
switch.
1b. When the park brake is released, the plunger
on the switch is extended, closing the N.C.
contacts within the switch. This completes part
of the ground path.
1c. The seat switch is the next part of the ground
path. The yellow wire/white trace connects the
park brake switch to the seat switch.
2. The seat switch is connected to the N.C. terminal
of the brake switch (yellow wire/white trace).
2a. When the seat is occupied, the N.C. contacts
within the seat switch are open.
2b. When the seat is vacant, the N.C. contacts
within the seat switch are closed. This com-
pletes the final leg of the ground path when
the park brake is not set, disabling the ignition.
108
Figure 7.22
Figure 7.23