Motion Control Switch; Purpose; How It Works; Testing - Toro 74161 Service Manual

ELECTRICAL SYSTEMS

Purpose

There are two motion control switches - one for each
lever. They sense the position of the motion control
levers.

How It Works

Each motion control switch has two pairs of contacts -
one normally open, one normally closed. When the
control handles are out, the contacts connected to the
light blue wires are closed providing a ground for the
start solenoid. When the handles are in these, contacts
are open preventing the starter from cranking. The
second pair of contacts, connected to the green wires,
prevent operation of the unit with the parking brake
applied. Moving the control levers in closes these
contacts sending a ground signal to the brake switch. If
the brake is applied, the ground signal is sent to the
engine kill terminal, shutting down the engine.

Testing

1. With the switch out, connect an ohmmeter across
each pair of terminals in turn. One pair should be
open with the switch plunger extended; the other
pair should be closed.
2. Push the switch plunger in; the conditions should
reverse.
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Motion Control Switch

Mid-Mount Z Service Manual