Seat Safety Switch - Craftsman 28906 Professional Shop Manual

ELECTRICAL SYSTEM
Hyrdostatic transmissions
Tractors equipped with a hydrostatic transmission have
the reverse switch mounted on the transmission, next
to the selector plate. See Figure 7.18.
Figure 7.18
Selector
Seat Safety Switch
The Seat Safety Switch is a double pole single throw
(DPST) switch. Both poles are normally closed and it is
located inside the seat. See Figure 7.20.
This switch has a yellow wire with black trace con-
nected to it. The yellow wire with black trace plugs into
the main harness by the starter solenoid and becomes
the red wire with black trace that goes directly to the
RMC module. See Figure 7.19.
The yellow wire with white trace is connected to
the safety circuit. When the seat is vacant, the
switch closes creating a ground path in series
with the brake switch. If the brake is OFF and
the seat is empty, the circuit is completed, short-
ing-out the primary windings of the ignition mod-
ule, turning-off the engine.
On tractors with an electric PTO, the yellow wire
connected to the seat safety switch sends a
ground signal to the RMC module when the seat
is vacant.
On tractors with a manual PTO, the yellow wire
goes to the PTO switch. A yellow wire from the
RMC module connects with the yellow wire from
the seat switch at the PTO switch. The other
side of the PTO switch is connected to the pri-
mary windings of the ignition module. If the seat
is empty or the RMC module senses an unsafe
condition while the PTO is on, a ground signal is
sent to the ignition module, turning-off the
engine.
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