Service Manual
Switch,
PTO
I
Switch
(D.P.D.T.)
E
Switch,
Seat
Seat Switch
(operator on)
Part
Number
78-3030
Purpose
Provides switching for two circuits: PTO clutch and the safety circuit.
Handle on switch requires the operator to provide two step input to help
prevent accidental engagement.
How
It
Works
Contacts inside the switch electrically connect various terminals. This
switch is a double pole, double throw (DPDT) switch. Here's what this
fancy terminology means:
Double Pole:
Think of this as the number of input lines. Notice that
the switch shown at left has two input lines.
In most applications, Toro makes use of the two input
lines, by placing pole
in
the
Pi0
circuit, and the other
half in the safety circuit.
Notice that this switch has two per pole.
The double throws give this switch the versatility to be
used as a NO (normally open) or NC (normally closed)
switch. This
is
advantageous in our tractor applications,
because the NC portion is used in the safety circuit,
while the NO portion is used in the PTO circuit.
Double Throw:
Think of this as the number of outputs lines per pole.
Testing
Disconnect the switch from the circuit and verify the following
connections with a volt/ohmmeter.
Switch Position
Connections
Off (lever down):
A+B,D+E
On (lever up) Run:
B+C,E+F
Part
Number
114240
Purpose
To close switch when operator sits on seat.
How
It
Works
The switch is open without an operator and closed with an operator.
The ribbon operates a friction type mechanism which, in turn, activates
the switch. A removable cover provides access to the switch contacts.
Note: Because of the friction mechanism, it is possible to get false
readings with the switch removed from the
switch in place.
Testing
Use a volt/ohmmeter to test for continuity.
1. Disconnect the switch from the circuit.
2. Leave the switch installed in the seat as
is removed.
seat. Perform testing with the
readings are possible
if
it
3.
The switch should test open (infinite resistance) without anyone on
the seat and closed
(0
resistance) with an operator. If not, replace the
switch.