General Information; Section Contents; System Description - Simplicity Broadmotor Series Service & Repair Manual

7 Electrical System Service

General Information

WARNING
Before beginning any service work, turn the PTO
off, set the parking brake, turn the ignition switch
off, remove the key, disconnect the spark plug
wire, and disconnect the negative battery cable.
GENERAL INFORMATION
The electrical system is a 12-volt, negative ground type.
Power for the lights and all electrical accessories is sup-
plied by a lead/acid-type battery which is charged by the
alternator.
This section covers the location, replacement, trou-
bleshooting, and testing procedures for the various elec-
trical components that are not associated with the
engine. Information on the engine, alternator, ignition
system, and starter can be found in the engine manufac-
turer's instructions.
It should be noted that when portions of the electrical
system are serviced, the negative battery cable should
be disconnected from the battery to prevent electrical
shorts and/or fires.

Section Contents

Section 7 contains the following sub-sections:
General Information – General overview of the electrical
system, principles of operation, and definitions of basic
electrical terms.
Exploded View Diagrams – Three-dimensional illustra-
tions of the electrical system components.
Wiring Diagrams – Schematics of the electrical system.
Linear Circuit Diagrams – Linear diagrams showing
electrical current path with the ignition switch in its three
positions.
Common "No Start" Circuit Tests – Linear diagrams
and procedures for troubleshooting a tractor that won't
start.
Component Location and Replacement – Location of
electrical components and explanations of how to
remove and replace them.
Troubleshooting Flow Charts – Checklist of component
tests to solve common electrical problems. Includes ref-
erences to specific component test procedures.
Component Tests – Testing procedures for specific
components.
Introduction
Before tackling any troublesome electrical circuit, first
study the appropriate wiring diagrams to get a complete
understanding of what makes up that individual circuit.
Malfunctions can often be narrowed down by noting if
other components, related to the circuit, are operating
properly. If several components malfunction at the same
time, chances are the problem is in the fuse/breaker,
common splice, or ground connection that is common to
all the malfunctioning components.
Electrical problems usually stem from simple causes,
such as loose or corroded connections, a blown fuse, a
tripped circuit breaker, or a bad relay. Visually inspect
the condition of all fuses, wires, and connections in a
suspected problem circuit before troubleshooting it.
Note: If testing instruments are going to be utilized, study
the diagrams ahead of time to plan where the necessary
connections will be made in order to accurately pinpoint
the trouble spot.
Before attempting to locate a problem with test instru-
ments, use the wiring diagram(s) to decide where to
make the connections.
TYPICAL TOOLS NEEDED
• VOM (volt-ohm meter, multi-meter, or equivalent).
• Test Light (circuit tester or continuity tester).
• Jumper wires with alligator clips at both ends.
• Power Supply (variable or 12VDC) or 12VDC Battery.
• Hydrometer.
• Wire Brush or Battery Terminal Brush.
• Clean Pencil Eraser.
• Standard Wrench Set.
• Standard Socket Set.
• Screwdriver Set.

System Description

All Broadmoor / 1600 / 2600 Series tractors have three
basic electrical circuits that represent the different electri-
cal functions of the tractor's electrical system. Each
function corresponds to the three positions of the ignition
switch: "START," "ON," and "OFF."
• START sends battery power to two sub-circuits:
1) Sends power through the safety switches (PTO,
foot pedal, PTO, and seat switches) to the #3 termi-
nal of the interlock module. If all safety switches are
closed, the interlock module activates the solenoid
sending power to the starter.
2) Sends power to the #7 terminal of the interlock mod-
ule (activating the module) and fuel solenoid (opening
the fuel solenoid).
• RUN connects battery power to two sub-circuits:
1) Connects the alternator to the battery through the
ignition switch. The alternator coil feeds power back
into the battery for recharging.
2) Sends power to the fuel solenoid and PTO clutch
circuit.
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