Objectives. Explain the principles of electricity.. Identify basic electric terms and components.. Perform fundamental electrical tests.. Describe the basic parts of an automotive battery.. Discuss safety precautions with working on batteries.. ID: 752892
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Explain the principles of electricity.
Identify basic electric terms and components.
Perform fundamental electrical tests.
Describe the basic parts of an automotive battery.
Discuss safety precautions with working on batteries.
Jump start a car using a second battery.
List the basic parts of the charging system.
Test charging system output with a voltage meter.
Describe starter drive operation
is the force, or electrical pressure, that causes electron flow.
This is similar to how water pressure causes water to squirt out of a garden hose.
Voltage is measure in volts.Slide4
is the flow of electrons from one atom to another. Current may be
AC or DC
. All automotive electricity is DC.Just as water flows through a garden hose, electrons flow through a wire in a circuit.
Current is measured in
, or amps for short.An increase in voltage causes an increase in current flow. A decrease in voltage causes a decrease in current flow.Slide5
Voltage and CurrentSlide7
A simple circuit consists of
such as a battery, alternator, or generator.2. A load
is an electrical device that uses electricity.
3. Conductors such as wires or metal parts, that carry current between the power source and the load.Slide8
Current can only flow through the system as long as there is a complete path to and from the batterySlide9
one wire circuit
, the vehicles frame or body serves as an electrical conductor.
A cable is used to connect the frame to the negative battery terminal.
Prevents having to use two wire circuits.
The body and/or frame must be iron or steel for this to work.Slide10
A magnetic field can be created using electricity.
Whenever current flows through a wire a magnetic field is created.
Magnetism is also used to create electricity. If a wire (conductor) is passed through a magnetic field, an electric current will be generated in the wire. This is called
Magnetism is used to operate many things in an automobile.Slide12
a circuit that has an “open” somewhere in it breaking the circuit. No current can flow through the circuit.
Closed circuit- a complete circuit that allows current to flow.
a short is an accidental connection that results in excessive current flow.Slide13
Open and Short CircuitsSlide14
is normally used to open and close a circuitSlide15
Fuses and Ckt BreakersSlide16
There are three basic types of fuses used in automobiles:
1. A cartridge fuse is a small glass cylinder with metal terminals at each end – used in older 70’s cars
blade fuse has two blades sticking out and is used in most of today’s cars.
3. An in-line fuse mounts in a small plastic case in one of the circuit wires. It is mostly used on aftermarket accessories.
Fuse rating is given in
amps. When replacing a fuse, ALWAYS replace it with a fuse of the same rating.Slide17
Circuit Protection- Fuses
Fuse- a fuse has a link that will melt and burn in half to stop current and prevent further circuit damage.Slide18
is an electrically operated switch.
It allows a small dash switch to control another circuit from a distant point.Slide19
Fuses are located throughout the entire vehicle. Common locations include the
behind the left or right kick panels
under the dash
. Fuses are usually grouped together and are often mixed in with other components like relays, circuit breakers, and fuse elements.
Fuse / relay block covers usually label the location and position of each fuse, relay, and fuse element contained within.Slide22
is used to quickly check a circuit for voltage.Slide23
is handy for testing switches, relays, wires, solenoids, and other electrical componentsSlide25
refers to any electrical component , assembly, circuit, or system that uses solid state devices.
means these devices have no moving parts to wear out.
Solid state components are much faster than electrical components.Slide27
Lights burn out with age.
Light bulbs come in lots of different types so the easiest way to get the right replacement is to take the old one into a parts place and let them match it.
Headlights are replaceable through the back of the light. Don’t touch the halogen bulb with your fingers. The oil will shorten the bulb life.Slide28
electro-chemical device that produces and stores electricity.A battery produces DC voltage which flows in one direction only.
is changed into electrical energy. When charging,
is converted in
Battery Terminals and Cables
provide a means of connecting the battery plates to the car’s electrical system.
Either two round posts or two side posts are used.
The positive post (marked +) is larger than the negative post (marked - )
The side posts have female threads that accept a special bolt with an easily rounded 8mm head.
The positive battery cable is normally
red and connects to the starter
The negative cable is normally
and connects to
Operate the starting motor, ignition system, electronic fuel injection system, and other electrical devices during engine cranking and starting.
Supply all electrical power when the engine is not running.
Help the charging system provide loads when current demands exceed the output of the alternator.
Store energy (electricity)for extended periods.Slide34
Battery Charge Indicator
battery charge indicator
, also called the
battery eye or test indicator shows the general charge condition of the battery.Slide35
Battery Terminals and CablesSlide36
As battery temperature drops, battery power is reduced.
At low temperatures, the
inside the battery is slowed. Also the
motor oil is thicker
increasing the amount of current needed to crank the engine.
The automotive battery requires special handling. The
inside the battery is a mixture of
sulfuric acid and
. Sulfuric acid is very corrosive; if it gets on your skin it should be flushed with water immediately;
if it gets in your eyes, you should immediately flush them thoroughly with water and see a doctor right away. In this situation, time is critical
If you work with a battery, you should have a mild solution of baking soda and water on hand and wash with that.
Sulfuric acid will eat through clothing, so it is advisable to wear old clothing when handling batteries.
It is also advisable to wear goggles and gloves while servicing the battery.
When charging, the battery will emit hydrogen gas; it is therefore extremely important to keep flames and sparks away from the battery.Slide38
A dead battery is a very common problem. Even though the lights and horn might work, there is not enough “juice” (current) in the battery to operate the starter.
Battery maintenance should be done periodically:
Checking the electrolyte level or the indicator eye.
Cleaning battery terminal connections.Cleaning the battery top.
Checking the battery hold down and tray.
Inspecting for physical damage to the case and terminals.Slide39
Cleaning Top of Case
Baking soda and
and remove the
Battery Terminal Test
A battery terminal test quickly checks for a poor connection between the battery cables and terminals.
Crank the engine.
Put your hands on the terminals and feel for heat.
Any sign of heat indicates a poor connection.This applies to any poor electrical connection.Slide42
Battery Post CleaningSlide43
Battery Terminal CleaningSlide44
Checking Battery Electrolyte
Unlike older batteries, maintenance free batteries do not need periodic electrolyte under normal conditions.
If the level is low in an older battery, fill the cells to the correct level using
A battery charger is used to re-energize a dead battery.
A slow charger, also called a
, feeds a small amount of current into the battery. Charging time is longer (about 12 hrs at 10 amps).However the chemical action inside the battery is improved as the active material is better plated.
A fast charge or boost charger forces a high current flow into the battery for rapid recharging.
If possible, slow charging should be done after a fast chargeSlide46
Charging A Battery
Before connecting a charger to a battery, make sure the charger is turned off. If a spark ignites any battery gas it could explode.
Make sure that you do not reverse the charger connections on the vehicles charging system or electronics could be damaged.
If you suspect a battery of being frozen (caused by a dead battery in cold weather), do not charge it. Charging a frozen battery can rupture the case and cause an explosion. Allow the battery to thaw first.Slide47
Side Post AdaptersSlide48
The more common reasons for a dead battery are:
Forgetting the headlights turned on after you park the car.
Forgetting a reading light or courtesy light turned on. This is easy to do since most cars have a feature that delays turning off the interior lights after you leave the car, so that you don't notice that you left a light turned on.
A corroded or loose connection between the battery and the cables attached to it.
A defective interior or trunk lamp switch that leaves the bulb lit.
A defective charging system that does not replenish the battery's charge.
An old battery that has lost its ability to maintain a full charge. Batteries have a life expectancy of 3 to 5 years.Slide49
If you aren’t sure what caused your battery to be dead, the first thing you can do is check the battery connections. Touching battery terminals with your hand will not give you a shock since we are dealing with only 12 to 14 volts and it would take more than that before you would feel it.
If however, you touch the battery terminal with anything metal and allow the metal to come into contact with any metal on the car, you will get a severe spark that could cause injury and possibly ignite the hydrogen gas causing an explosion.
Grab each terminal and feel if the connection is loose on the battery. If you notice that one of the terminals is loose, just by moving it, you may be able to establish a good enough connection to start the car by pushing down and twisting the terminal.Slide50
In emergency situations it may be necessary to jump start a vehicle by connecting another battery to the discharged battery.
red jumper cable
to the positive terminal of the dead battery
red jumper cable to the good battery. Connect the
Find a place on the dead car to connect the other
away from the battery, either on the
engine block or a metal bracket
that is directly attached to the engine. You most likely will see some small sparking.
If you get a big spark, there is something not connected properly.
By connecting the last negative jumper cable to a ground away from battery, any spark will be further away from the explosive battery gas.
Do not short jumper cables together or connect them backwards. This could cause serious damage to the charging or computer systems.
Do not assume that red wire connected to the battery is + or the black is -.
If the cables begin to get hot, discontinue the boost immediately: the cables are not heavy duty enough to do the job.
Once the disabled car is running, first remove the negative cable from the engine block of the problem car, then remove the negative cable from the other car.
Finally, remove the positive clamps from both cars.
When shopping for booster cables, look for heavy cable with insulated wire that is at least 6 gauge, with 4 gauge being better. (the lower the cable gauge, the thicker the wire). Make sure that the wire goes all the way through the clamp and is connected directly to the jaw. If the wire is connected only to the clamp grip, do not buy it. Good jumper cables will cost more than $20 with professional quality cables costing $30 or more. There are plenty of cables that cost as little as $5 to $10. Stay away from those.Slide53
Batteries on newer cars are not always easily accessible, but when this is the case, they will have a battery tap somewhere in the engine compartment. The positive side will usually be clearly marked under a red plastic protective cover. The negative side may or may not be there, but you can always connect to the engine block or metal brackets that are directly attached to the engine.Slide54
Functions of the Charging System
Recharge the battery after engine cranking or after use of the electrical accessories with the engine shut off.
It supplies the cars electricity when the car is running.Slide56
Basic Charging System
is the piece that makes the electricity in a running car.Slide57
Three Types BeltsSlide59
informs the driver of the operating condition of the charging system.
An alternator warning light is wired into the charging system so that it will glow when alternator output drops to a specified level.When a charging problem is indicated, you can still drive a short distance to find help unlike an oil pressure or coolant temperature problem which can cause serious engine damage if you continue to drive. The worst that can happen is that you get stuck in a bad location.Slide60
The voltmeter shows the driver alternator voltage output.
Alternator voltage is usually 13-15 volts.
If the voltage drops below 12.5, it means that the battery is providing some of the current. If this happens for an extended period, the battery will run down and may not have enough of a charge to start the car after shutting it off.
If the voltage ever goes above 15 volts, there is a problem with the voltage regulator.Slide61
Charging System Diagnosis
There are four symptoms of charging system problems:
1. Dead battery
2. Overcharged battery- overheats, or frequent water
3. Abnormal noises-grinding, squealing, buzzing4. Indicator shows problems-light glows all the time or there is an incorrect indicator reading.Slide62
A loose alternator belt may squeal or flap and prevent normal charging.
When inspecting a belt, look for cracks, glazing (hard shiny surfaces), grease or oil contamination, and deterioration.
If needed adjust the belt tension by loosening the alternating mounting and adjusting bolts. Then pry on a strong surface. Serpentine belts have
Tighten any other mounting bolts and recheck the belt tension. The belt should deflect
½ inch when pressed with a thumb.Slide63
Adjusting Belt TensionSlide65
A dead battery is one of the most common reasons the starting system fails to crank the engine.
that occurs after momentary engine cranking may be to a bad overrunning clutch or a worn pinion gear.A metallic grinding noise
may be caused by broken flywheel teeth or worn pinion gear teeth. The grinding may caused as the gears clash together.
Normal cranking without starting is usually not caused by the starting system.Slide68
Starting Headlight Test
starting headlight test
will quickly indicate the causes of trouble in a starting system.
Turn on the headlights and try to start the engine. Note any sounds and watch the brightness of the lights.
No cranking with no headlights indicates a dead battery or an open electrical system (blown main fuse).
If the headlights go out when cranking the battery may be weak, the starter bad, or the engine may be at fault.
If the lights stay bright but the engine doesn’t crank properly, a bad ignition switch or neutral safety switch.Slide69
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