List precautions to avoid short circuits
when working on an electrical system
Remove rings, watches and jewelry
Remove battery ground strap if working on
or around any live circuit such as the
alternator, starter, ignition switch etc.
List precautions to take before
starting an engine inside the shop
Sit in operator seat to maintain control of
vehicle
Insure all test leads are clear of fan, belts
and exhaust
Insure no other person is working around
vehicle
Insure that there is an exhaust hose attached
and ventilation fans are turned on
List precautions to take when
working around a running engine
Avoid working near fan or fan belts
Do not reach over fan or moving pulleys
Properly ventilate exhaust
Insure vehicle can not roll
Pay special attention to test leads
Watch out for hot exhaust manifold
List precautions to take when
working around a running engine
Turn OFF engine when connecting or
moving testing leads and equipment
Only run engine during specific testing
and turn off when done with test
Control any loose clothing or long hair
Basic Electrical Theory
What is Voltage?
What is an Ampere
Amperage or Electrical Current
the Intensity of the electron movement
between atoms
one amp = 6,280,000,000,000,000,000
electrons per second
Carl Sagan would say that one amp equals
over six billion, billion electrons per second
Amperage
The more electrons moving from atom to
atom, the more current or Amperage
How many electrons (amps) move is
decided by the pressure (volts) and the
resistance to the flow of electrons
Low Amps
High Amps
Amperage
Higher Voltages (pressure) will cause more amps
(electrons) to flow
Increasing the resistance to the electron
movement will lower Amp flow
Which Way does Current Flow?
Quick Quiz
What is electricity?
The movement of electrons between atoms
What causes electrons to move between atoms?
Voltage
A bunch of extra electrons (negative ions)
An area that is missing electrons (positive ions)
Lab #4
Series Circuits