Starter Solenoid & Starting System; Purpose; Location; How It Works (Solenoid Only) - Toro TimeCutter SW4200 Service Manual

ELECTRICAL
Starter Solenoid & Starting System

Purpose

The solenoid's purpose is a remote switch to connect
the battery to the starter motor on the engine when the
ignition switch is turned to "START". The solenoid is
used to protect the ignition switch from the high current
drawn by the starter motor.

Location

The starter solenoid is located under the operator's seat,
near the brake actuator module and battery (Fig. 165).

How It Works (solenoid only)

The solenoid has two primary parts. One, a coil of wire
is wrapped around an iron core. Whenever 12 volts is
7
applied to the coil, it becomes a magnet. The other part
is a bar type switch. Because it has a large contact area
with the contact terminals, it can easily handle the high
current loads required by the starter motor of the engine.
When 12 volts is applied to the coil, it becomes an elec-
tromagnet. This quickly pulls the contact bar toward the
contacts and closes the switch. When power is removed
from the coil, the spring loaded bar returns to its
"normally open" position. The solenoid closes and opens
the switch very quickly. This minimizes the "arcing" that
can damage other types of switches.
The ignition switch is protected because only a small
amount of current is needed to activate the coil.
7-10
Fig. 165 PICT-1021

Starter Solenoid Testing (solenoid only)

1. Disconnect solenoid from the wiring harness.
2. With a multimeter (ohms setting), check to ensure
that terminals "c" and "d" are open (no continuity).
3. Apply +12 VDC to terminal "a" and ground terminal
"b". Terminals "c" and "d" should now be closed
(continuity) (Fig. 166).
Fig. 166
Toro TimeCutter SW/SWX Service Manual
xl solenoid