Toro Z Master Z400 Series Service Manual page 147

ELECTRICAL
How It Works
The solenoid has two primary parts. One is a coil of
wire wrapped around an iron core. Whenever 12 volts is
applied to the coil, it becomes a magnet. The other part
is a bar type switch (Fig. 405).
Because it has a large contact area with the contact
terminals it can easily handle the high current loads
required by the starter motor. When 12 volts is applied
to the coil, it becomes an electromagnet. This quickly
pulls the bar toward 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
6
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.
6-14
Fig 405 xl solenoid a
Testing
1. Disconnect the solenoid from the wiring harness.
2. With a multimeter (ohms setting), check to ensure
that terminals "C" and "D" are open (no continuity)
(Figure 20).
3. Apply +12 VDC between terminal "A" and ground
terminal "B". Terminals "C" and "D" should now be
closed (continuity) (Figure 20).
4. You should be able to hear the solenoid switch
"click" when you make the connection (Fig. 406).
C
A
Fig 406
A & B Coil Terminals
Z Master Z400 Service Manual
D
B
PICT-0204 rev
C & D Contact Terminals