ELECTRICAL SYSTEMS OPERATION
Nearly every component of the models covered in this manual is affected by the electrical system. These
components and their electrical connections are described as part of the following electrical subsystems:
Battery System Operation (page 1-48).
Starting System Operation (page 1-49).
Ether Starting System Operation (page 1-50).
Generating System Operation (page 1-51).
Directional Signal System Operation (page 1-52).
Heating System Operation (page 1-53).
Indicator, Gauge, and Warning System Operation (page 1-54).
Trailer and Semitrailer Connection System Operation (page 1-56).
Electrical Terms and Definitions.
The following electrical terms and definitions will be frequently referred to throughout this section and should
be understood before proceeding:
Alternating Current (AC signal) - Current in a circuit that flows, in one direction first, then in the other direction.
Circuit - A complete path for electric current flow between components.
Circuit Breaker - An automatic switch that interrupts current flow in a circuit when the current limit is exceeded.
Direct Current (DC signal) - Current in a circuit that flows in one direction.
Female Connector - One-half of a connector which fits over the other half.
Ground - A common return to complete a path for current flow in a circuit.
Harness - A group of wires connected between devices that are bundled and routed together to prevent damage and
make repair and replacement easier.
Male Connector - One-half of a connector which fits the other half.
Polarity - The direction current flows in a circuit (usually positive to negative).
Relay - An electromagnetic device that operates like an automatic switch to control the flow of current in the same or
Reverse Polarity - The condition that exists when circuit polarity is connected opposite of that which was intended.
Sending Unit - A device that produces an electrical signal and sends this signal to the device which will make use of it.
Sensor - An electrical sensor takes a physical condition (temperature, oil presence or absence) and converts this into an
Splice - A permanent physical connection of two or more wires.
Terminal - Fastener at end of wire used to connect the wire to an electrically-powered device.