Discovery I (LJ) V8-4.0L (1996)
A relay is an electromagnetic switching device that allows a low current circuit to operate a high current circuit. Relays allow smaller switches and
wiring to be used in control circuits. The most common relays are the 4- or 5-pin type. The 4-pin relay has 1 output. The 5-pin relay has 2 outputs, an
energized output and a relaxed or de-energized output. There are also specialized relays that may have diodes or resistors to control current flow.
RESISTORS
A resistor is an electrical component that slows current flow through a circuit. Resistors are used to drop voltage and amperage within an electrical
circuit.
RESISTOR COLOR CODE
First & Second Color Band
Third Color Band
Black
0
Black
0
Brown
1
Brown
x10
Red
2
Red
x100
Orange
3
Orange
x1000
Yellow
4
Yellow
x10,000
Green
5
Green
x100,000
Blue
6
Blue
x1,000,000
Violet
7
Silver
x100
Gray
8
Gold
x10
White
9
Fourth color band = Tolerance
Gold - 5% Silver - 10% None - 20%
SEMICONDUCTORS
Materials used in electrical circuitry differ greatly in their capacity to conduct electricity, ranging from good metallic conductors to the insulators.
Between metallic conductors and insulators we have the semiconductors. They are named semiconductors because they do not conduct as well as
conductors but as a rule conduct better than insulators.
Semiconductors which conduct free electrons are known as N-Type (N = negative). Semiconductors whose conductivity is based on "holes" are known
as P-Type (P = positive). A "hole" represents a charge deficit of one electron. The electrons in this type of semiconductor are firmly bonded in the atom
so therefore cannot contribute to electrical conduction. Since the "holes" are tightly surrounded by electrons, the vicinity has a negative charge. The
"hole," therefore, has a positive charge.
Semiconductors play a very important role in automotive electronics. Without them it would not be possible to have alternators, ignition modules,
electronically tuned radios, electronic fuel injection systems, etc. The four most common types of semiconductors used in automobiles are Diodes,