Load - Chevrolet Trailblazer Service Manual

may use relays are the horn, headlights, starter, electric fuel pump and other high draw
circuits.
The internal components of a relay consist of a coil and a switch. These two components
are linked together so that when one operates, the other operates at the same time. The
large wires in the circuit are connected from the battery to one side of the relay switch (B+)
and from the opposite side of the relay switch to the load (component). Smaller wires are
connected from the relay coil to the control switch for the circuit and from the opposite side
of the relay coil to ground

Load

Every electrical circuit must include a "load'' (something to use the electricity coming from
the source). Without this load, the battery would attempt to deliver its entire power supply
from one pole to another. This is called a "short circuit." All this electricity would take a
short cut to ground and cause a great amount of damage to other components in the
circuit by developing a tremendous amount of heat. This condition could develop sufficient
heat to melt the insulation on all the surrounding wires and reduce a multiple wire cable to
a lump of plastic and copper.