Transcript chapter quiz

OBJECTIVES
After studying Chapter 22, the reader should be able to:
1. Prepare for ASE Electrical/Electronic Systems (A6)
certification test content area “E” (Lighting System
Diagnosis and Repair).
2. Determine which replacement bulb to use on a given
vehicle.
3. Describe how interior and exterior lighting systems work.
4. Read and interpret a bulb chart.
5. Discuss troubleshooting procedures for lighting and
signaling circuits.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
LIGHTING
•
The headlight switch controls the following lights
on most vehicles:
1.
2.
3.
4.
5.
6.
Headlights
Taillights
Side-marker lights
Front parking lights
Dash lights
Interior (dome) light(s)
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
BULB NUMBERS
• Amber-color bulbs that use
natural amber glass are
indicated with an “NA” for
natural amber at the end of
the number (for example,
1157NA).
• A less expensive amber
bulb that uses painted
glass is labeled “A” for
amber (for example,
1157A).
Automotive Electricity and Electronics, 2/e
By James D Halderman
FIGURE 22-1 Bulbs that have the same trade
number have the same operating voltage and
wattage. The NA means that the bulb uses a
natural amber glass ampoule with clear turn
single lenses.
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
BULB NUMBERS
• The amount of light produced by a bulb is determined by
the resistance of the filament wire, which also affects the
amount of current (in amperes) required by the bulb.
FIGURE 22-2 This single-filament bulb is being
tested with a digital multimeter set to read
resistance in ohms. The reading of 1.3 ohms is
the resistance of the bulb when cold. As soon as
current flows through the filament, the resistance
increases about 10 times. It is the initial surge of
current flowing through the filament when the
bulb is cool that causes many bulbs to fail in
cold weather as a result of the reduced
resistance. As the temperature increases, the
resistance increases.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
BULB NUMBERS
FIGURE 22-3 Close-up of a dual-filament
(double-filament) bulb (1157) that failed.
Notice that one filament (top) broke from its
mounting and melted onto the lower
filament. This bulb caused the dash lights
to come on whenever the brakes were
applied.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
BULB NUMBERS
• The correct replacement bulb for a vehicle is
usually listed in the owner’s manual or service
manual.
FIGURE 22-4 Bulbs 1157 or 2057 are
typically used for taillight and front parking
lights. These bulbs contain both a lowintensity filament for taillights or parking
lights and a high-intensity filament for brake
lights and turn signals.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
BULB NUMBERS
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
BULB NUMBERS
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
BULB NUMBERS
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
WEIRD PROBLEM—EASY SOLUTION
• A General Motors minivan had the following
electrical problems.
– The turn signals flashed rapidly on the left side.
– With the ignition key off, the lights-on warning chime
sounded if the brake pedal was depressed.
– When the brake pedal was depressed, the dome light
came on.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
WEIRD PROBLEM—EASY SOLUTION
• All of these problems
were caused by one
defective 2057 dualfilament bulb.
FIGURE 22-5 Corrosion caused the two
terminals of this dual-filament bulb to be
electrically connected.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
WEIRD PROBLEM—EASY SOLUTION
• Apparently, the two
filaments were electrically
connected through the
corrosion observed
between the terminals of
the bulb.
• This caused the electrical
current to feed back from
the brake light filament into
the taillight circuit, causing
all the problems.
Automotive Electricity and Electronics, 2/e
By James D Halderman
FIGURE 22-6 Often the best diagnosis is a
thorough visual inspection. This bulb was found
to be filled with water, which caused weird
problems.
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
BRAKE LIGHTS
• The brake light switch is a normally open (N.O.)
switch but is closed when the driver depresses the
brake pedal.
• The brake switch is also used as an input switch
(signal) for the following:
1. Cruise control (deactivates when the brake pedal is
depressed)
2. Antilock brakes (ABS)
3. Brake shift interlock (prevents shifting from “park”
position unless the brake pedal is depressed)
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
NO CRUISE CONTROL? CHECK THE THIRD BRAKE LIGHT
• A common cause of an inoperative cruise control,
especially on General Motors vehicles, is a burned
out bulb in the third stop light.
• The cruise control uses the filaments of the third
brake bulb (CHMSL) as a ground and shuts off the
cruise if the bulbs are burned out (open).
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
NO CRUISE CONTROL? CHECK THE THIRD BRAKE LIGHT
FIGURE 22-7 Typical brake light and taillight circuit showing the brake
switch and all of the related circuit components.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
HEADLIGHT SWITCHES
• A circuit breaker is built into most headlight
switches to protect the headlight circuit.
FIGURE 22-8 Typical headlight
circuit diagram. Note that the
headlight switch is represented by a
dotted outline indicating that other
circuits (such as dash lights) also
operate from the switch.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
HEADLIGHT SWITCHES
Removing a Headlight Switch
• Most dash-mounted headlight switches can be
removed by first removing the dash panel.
• Other headlight switch knobs are removed by
depressing a spring-loaded release, which allows
for removal of the entire headlight switch knob and
shaft.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
HEADLIGHT SWITCHES
Removing a Headlight Switch
FIGURE 22-9 To remove the headlight switch from a vehicle that uses a knob and
shaft, a release button has to be pushed to release the shaft. After the knob and shaft
assembly has been removed, then the retaining nut can be removed from the
headlight switch so it can be removed from the dash.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
SEALED-BEAM HEADLIGHTS
• If either the high-beam
or the low-beam
filament is burned out,
the ohmmeter will
indicate infinity (OL).
FIGURE 22-10 Typical headlight socket
connections. Some vehicles may be different.
The high- and low-beam connections must be
determined by visual inspection.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
HEADLIGHT AIMING
• According to U.S.
federal law, all
headlights, regardless
of shape, must be able
to be aimed using
headlight aiming
equipment.
FIGURE 22-11 All vehicles sold in the United
States must have provision for the use of
mechanical aiming devices. Even the halogen
bulb units with plastic or glass lenses have
locating points and adjustment screws.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
HEADLIGHT AIMING
FIGURE 22-12 Typical headlight-aiming diagram as found in a service manual.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
HEADLIGHT AIMING
FIGURE 22-13 Many composite headlights have
a built-in bubble level to make aiming easy and
accurate.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
COMPOSITE HEADLIGHTS
• Composite
headlights are
constructed using a
replaceable bulb
and a fixed lens
cover that is part of
the vehicle.
FIGURE 22-14 A typical composite headlamp
assembly. The lens, housing, and bulbs sockets
are usually included as a complete assembly.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
HALOGEN SEALED-BEAM HEADLIGHTS
• Halogen sealed-beam headlights are brighter and
more expensive than normal headlights.
• Because of their extra brightness, it is common
practice to have only two headlights on at any one
time, because the candlepower output would
exceed the maximum U.S. federal standards if all
four halogen headlights were on.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
DIAGNOSE BULB FAILURE
• Some causes for halogen bulb failure and their
indications are as follows:
– Gray color—low voltage to bulb (check for corroded
socket or connector)
– White (cloudy) color—indication of an air leak
– Broken filament—usually caused by excessive vibration
– Blistered glass—indication that someone has touched the
glass
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
DIAGNOSE BULB FAILURE
FIGURE 22-15 Notice the
broken filament in this
halogen headlight bulb.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
HIGH-INTENSITY DISCHARGE HEADLIGHTS
Parts and Operation
• High-intensity discharge
(HID) headlights produce a
distinctive blue-white light
that is crisper, clearer, and
brighter than light produced
by a halogen headlight.
• The HID lighting system
consists of the discharge
arc source, igniter, ballast,
and headlight assembly.
Automotive Electricity and Electronics, 2/e
By James D Halderman
FIGURE 22-16 The ignitor contains the
ballast and transformer needed to provide
high-voltage pulses to the arc tube bulb.
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
HIGH-INTENSITY DISCHARGE HEADLIGHTS
Parts and Operation
• The color of light is expressed in temperature using
the Kelvin scale.
• Typical color temperatures include:
–
–
–
–
Daylight—5,400°K
HID—4,100°K
Halogen—3,200°
Incandescent (tungsten)—2,800°K
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
HIGH-INTENSITY DISCHARGE HEADLIGHTS
Parts and Operation
• The HID ballast is powered
by 12 volts from the
headlight switch on the
body control module. The
HID headlights operate in
three stages or states.
– 1. Start-up or stroke state
– 2. Run-up state
– 3. Steady state
FIGURE 22-17 HID (xenon) headlights
emit a whiter light than halogen
headlights and usually look blue
compared to the parking light on the
side.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
HIGH-INTENSITY DISCHARGE HEADLIGHTS
Start-Up or Stroke State
• When the headlight switch is turned to the on
position, the ballast may draw up to 20 amperes at
12 volts.
• The increased voltage is used to create an arc
between the electrodes in the bulb.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
HIGH-INTENSITY DISCHARGE HEADLIGHTS
Run-Up State
• After the arc is established, the ballast provides a
higher than steady state voltage to the arc tube to
keep the bulb illuminated.
• On a cold bulb, this state could last as long as 40
seconds.
• On a hot bulb, the run-up state may last only 15
seconds.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
HIGH-INTENSITY DISCHARGE HEADLIGHTS
Steady State
• The steady state phase begins when the power
requirement of the bulb drops to 35 watts.
• The ballast provides a minimum of 55 volts to the
bulb during steady state operation.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
HIGH-INTENSITY DISCHARGE HEADLIGHTS
Failure Symptoms
• The following symptoms indicate bulb failure.
– A flickering light
– The lights go out (which is caused when the ballast
assembly detects repeated bulb restrikes)
– Color change to a dim pink glow
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
HIGH-INTENSITY DISCHARGE HEADLIGHTS
Diagnosis and Service
• High-intensity discharge headlights will change
slightly in color with age.
• This color shift is usually not noticeable unless one
headlight arc tube assembly has been replaced due
to a collision repair, and then the difference in color
may be noticeable.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
ADAPTIVE FRONT LIGHTING SYSTEM
Parts and Operation
• A system that mechanically moves the headlights to follow
the direction of the front wheels is called adaptive (or
advanced) front light system, or AFS.
FIGURE 22-18 Adaptive front lighting systems rotate the low-beam headlight in the direction of travel.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
ADAPTIVE FRONT LIGHTING SYSTEM
Parts and Operation
• AFS is often used in addition to self-leveling motors
so that the headlights remain properly aimed
regardless of how the vehicle is loaded.
• Without self-leveling, headlights would shine higher
than normal if the rear of the vehicle is heavily
loaded.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
ADAPTIVE FRONT LIGHTING SYSTEM
Parts and Operation
FIGURE 22-19 A typical adaptive front lighting system
uses two motors—one for the up and down movement
and the other for rotating the low-beam headlight to the
left and right.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
ADAPTIVE FRONT LIGHTING SYSTEM
Diagnosis and Service
• The first step when
diagnosing an AFS system
fault is to perform the
following visual inspection.
– Start by checking that the
AFS system is switched on.
Most AFS headlight systems
are equipped with a switch
that allows the driver to turn
the system on and off.
FIGURE 22-20 Typical dash-mounted switch
that allows the driver to disable the front lighting
system.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
ADAPTIVE FRONT LIGHTING SYSTEM
Diagnosis and Service
– Check that the system performs a self-test during startup.
– Verify that both low-beam and high-beam lights function
correctly. The system may be disabled if a fault with one
of the headlights is detected.
– Use a scan tool to test for any AFS-related diagnostic
trouble codes. Some systems allow the AFS to be
checked and operated using a scan tool.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
DAYTIME RUNNING LIGHTS
• Daytime running lights (DRLs) involve operating
front parking lights or the headlights (usually at
reduced current and voltage) when the vehicle is
running.
• To avoid having the lights on during servicing, some
systems will turn off the headlights when the parking
brake is applied.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
DAYTIME RUNNING LIGHTS
FIGURE 22-21 Typical daytime
running light (DRL) circuit. Follow
the arrows from the DRL module
through both headlights. Notice
that the left and right
headlights are connected in
series, resulting in increased
resistance, less current flow, and
dimmer than normal lighting.
When the normal headlights are
turned on, both headlights receive
full battery voltage, with the left
headlight grounding through the
DRL module.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
DIMMER SWITCHES
• The headlight switch controls the power or hot side
of the headlight circuit.
• The current is then sent to the dimmer switch, which
allows current to flow to either the high-beam or the
lowbeam filament of the headlight bulb,
• To replace most of these types of dimmer switches,
the steering column needs to be lowered slightly to
gain access to the switch itself, which is also
adjustable for proper lever operation.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
DIMMER SWITCHES
FIGURE 22-22 Most vehicles use positive switching of the high- and low-beam
headlights. Notice that both filaments share the same ground connection. Some
vehicles use negative switching and place the dimmer switch between the filaments
and the ground.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
STOP LAMP AND TURN SIGNALS
• When the brakes are
applied, the brake switch is
closed and the stop lamps
light.
• The brake switch receives
current from a fuse that is
hot all the time.
FIGURE 22-23 The brake lights are powered
directly from the brake switch on a vehicle that
uses separate bulbs for brake lights and turn
signals.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
STOP LAMP AND TURN SIGNALS
• The turn signal switch
is mounted within the
steering column and
operated by a lever.
FIGURE 22-24 The typical turn signal switch
includes various springs and cams to control the
switch and to cause the switch to cancel after a
turn has been completed.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
STOP LAMP AND TURN SIGNALS
• In systems using separate
filaments for the stop and
turn lamps, the brake and
turn signal switches are not
connected.
• If the vehicle uses the same
filament for both purposes,
then brake switch current is
routed through contacts
within the turn signal
switch.
Automotive Electricity and Electronics, 2/e
By James D Halderman
FIGURE 22-25 When the stop lamps and
turn signals share a common bulb filament,
stop light current flows through the turn
signal switch.
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
STOP LAMP AND TURN SIGNALS
• By linking certain contacts,
the bulbs can receive either
brake switch current or
flasher current, depending
upon which direction is
being signaled.
FIGURE 22-26 When a right turn is signaled, the
turn signal switch contacts send flasher current
to the right-hand filament and brake switch
current to the left-hand filament.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
STOP LAMP AND TURN SIGNALS
• Aftermarket
replacement LED bulbs
that are used to replace
conventional bulbs may
require the use of a
different type of flasher
unit due to the reduced
current draw of the LED
bulbs.
FIGURE 22-27 A replacement LED taillight bulb
is constructed of many small individual lightemitting diodes.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
FLASHER UNITS
• A turn signal flasher
unit is a metal or plastic
can containing a switch
that opens and closes
the turn signal circuit.
FIGURE 22-28 Two styles of two-prong flashers.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
FLASHER UNITS
Bimetallic flashers
• Bimetallic flashers units were the first type used and
have generally been replaced with other types that
have a longer service life.
• If one bulb burns out, either in the front or rear of
the vehicle, the flasher will not flash on the side with
the bad bulb.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
FLASHER UNITS
Hybrid Flasher (Flasher relay)
• A hybrid flasher, also called a flasher relay, is a
type of flasher unit that contains an electronic timing
circuit and a mechanical relay which opens and
closes the turn signal circuit.
• If all bulbs are burned out, the flasher will not flash
at all.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
FLASHER UNITS
Solid-State Flashers
• Solid state flashers use an electronic switching
circuit and an electronic timing circuit to operate the
turn signals.
• Because these units do not use a mechanical
switch or contacts to open and close the turn signal
circuit, these flashers last a long time, but cost more
than bimetallic or hybrid units.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
FLASHER UNITS
Hazard Warning Flasher
• A typical hazard warning
flasher is also called a
parallel or variable-load
flasher because there is
a resistor in parallel with
the contacts to provide a
control load and,
therefore, a constant
flash rate, regardless of
the number of bulbs
being flashed.
Automotive Electricity and Electronics, 2/e
By James D Halderman
FIGURE 22-29 A hazard flasher uses a parallel
resistor across the contacts to provide a
constant flashing rate regardless of the number
of bulbs used in the circuit.
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
FLASHER UNITS
Combination Turn Signal and
Hazard Warning Flasher
• The combination flasher is a device which combines
the functions of a turn signal flasher and a hazard
warning flasher into one package.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
FLASHER UNITS
Electronic Flasher Replacement
Units
• Older vehicles (and a few newer ones) use thermal
(bimetal) flashers that use heat to switch on and off.
• Newer vehicles use electronic flashers that use
microchips to control the on/off function.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
FLASHER UNITS
Electronic Flasher Replacement
Units
• Other common turn
signal problems and
possible solutions
include the following:
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
WHY DOES THE SIDE-MARKER LIGHT ALTERNATELY FLASH?
• The side marker light goes out when the lights are on and
the turn signal is flashing because there are 12 volts on both
sides of the bulb.
FIGURE 22-30 The sidemarker light goes out when
there is voltage at both points X
and Y. These opposing
voltages stop current flow
through the side-marker light.
The left turn light and left park
light are actually the same bulb
(usually a 2057) and are shown
separately to help explain how
the side-marker light works on
many vehicles.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
COURTESY LIGHTS
• Courtesy light is a generic
term primarily used for
interior lights, including
overhead (dome) and
under-the-dash (courtesy)
lights.
FIGURE 22-31 A typical courtesy light doorjamb switch. Newer vehicles use
the door switch as an input to the vehicle computer and the computer turns
on or off the interior lights. By placing the lights under the control of the
computer, the vehicle engineers have the opportunity to delay the lights after
the door is closed and to shut them off after a period of time to avoid draining
the battery.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
ILLUMINATED ENTRY
• Some vehicles are equipped with illuminated entry,
meaning the interior lights are turned on for a given
amount of time when the outside door handle is
operated while the doors are locked.
• Most vehicles equipped with illuminated entry also
light the exterior door keyhole.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
FIBER OPTICS
• Fiber optics is the transmission of light through
special plastic (polymethyl methacrylate) that keeps
the light rays parallel even if the plastic is tied in a
knot.
• The source of the light can be any normally
operating light bulb, which means that one bulb can
be used to illuminate many areas.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
AUTOMATIC DIMMING MIRRORS
Parts and Operation
• Automatic dimming mirrors use electrochromic
technology to dim the mirror in proportion to the
amount of headlight glare from other vehicles at the
rear.
• If automatic dimming mirrors are used on the
exterior, the sensors in the interior mirror and
electronics are used to control both the interior and
exterior mirrors.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
AUTOMATIC DIMMING MIRRORS
Diagnosis and Service
• If a customer concern states that the mirrors do not
dim when exposed to bright headlights from the
vehicle behind, the cause could be sensors or the
mirror itself.
• One typical fault that can occur to automatic
dimming mirrors is that a crack can occur in the
mirror assembly allowing the gel to escape from
between the two layers of glass.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
FEEDBACK
• When current that lacks a good ground goes
backward along the power side of the circuit in
search of a return path (ground) to the battery, this
reverse flow is called feedback or reverse-bias
current flow.
• Feedback can cause other lights or gauges that
should not be working to actually work.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
FEEDBACK
Feedback Example
• A customer complained that when the headlights
were on, the left turn signal indicator light on the
dash remained on.
• The cause was found to be a poor ground
connection for the left front parking light socket.
• Cleaning or replacing the socket usually solves the
problem if the ground wire for the socket is making
a secure chassis ground connection.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
LIGHTING SYSTEM SYMPTOM GUIDE
• The following list will assist technicians in troubleshooting
lighting systems.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
TAILLIGHT BULB REPLACEMENT
Step-by-Step
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
TAILLIGHT BULB REPLACEMENT
Step-by-Step
Automotive Electricity and Electronics, 2/e
By James D Halderman
cont
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
TAILLIGHT BULB REPLACEMENT
Step-by-Step
Automotive Electricity and Electronics, 2/e
By James D Halderman
cont
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
OPTICAL HEADLIGHT AIMING
Step-by-Step
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
OPTICAL HEADLIGHT AIMING
Step-by-Step
Automotive Electricity and Electronics, 2/e
By James D Halderman
cont
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
OPTICAL HEADLIGHT AIMING
Step-by-Step
Automotive Electricity and Electronics, 2/e
By James D Halderman
cont
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
OPTICAL HEADLIGHT AIMING
Step-by-Step
Automotive Electricity and Electronics, 2/e
By James D Halderman
cont
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
OPTICAL HEADLIGHT AIMING
Step-by-Step
Automotive Electricity and Electronics, 2/e
By James D Halderman
cont
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
OPTICAL HEADLIGHT AIMING
Step-by-Step
Automotive Electricity and Electronics, 2/e
By James D Halderman
cont
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
SUMMARY
1. Automotive bulbs are identified by trade numbers.
2. The trade number is the same regardless of manufacturer
for the exact same bulb specification.
3. Daytime running lights (DRLs) light the headlights, usually
at reduced intensity, when the engine is running or the
vehicle is moving.
4. High-intensity discharge (HID) headlights are brighter and
have a blue tint.
5. One defective turn signal bulb causes the turn signal on the
affected side to stop blinking (flashing).
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
REVIEW QUESTIONS
1. Explain why the exact same trade number of bulb
should be used as a replacement.
2. Explain why you should not touch a halogen bulb
with your fingers.
3. Describe how to diagnose a turn signal operating
problem.
4. Discuss how to aim headlights on a vehicle
equipped with aerodynamic-style headlights.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
1. Technician A says that the bulb trade number is the
same for all bulbs of the same size. Technician B
says that a dual-filament bulb has different
candlepower ratings for each filament. Which
technician is correct?
a)
b)
c)
d)
Technician A only
Technician B only
Both Technicians A and B
Neither Technician A nor B
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
2. Two technicians are discussing flasher units.
Technician A says that only a DOT-approved
flasher unit should be used for turn signals.
Technician B says that a parallel (variable-load)
flasher will function for turn signal usage, although
it will not warn the driver if a bulb burns out. Which
technician is correct?
a)
b)
c)
d)
Technician A only
Technician B only
Both Technicians A and B
Neither Technician A nor B
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
3. Interior overhead lights (dome lights) are operated
by door jamb switches that _____.
a)
b)
c)
d)
Complete the power side of the circuit
Complete the ground side of the circuit
Move the bulb(s) into contact with the power and ground
Complete either a or b depending on application
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
4. Electrical feedback is usually a result of
_____.
a)
b)
c)
d)
Too high a voltage in a circuit
Too much current (in amperes) in a circuit
Lack of a proper ground
Both a and b
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
5. Which bulb is brightest? (see the bulb table)
a)
b)
c)
d)
194
168
194NA
1157
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
6. If a 1157 bulb were to be installed in a left front
parking light socket instead of a 2057 bulb, what
would be the most likely result?
a)
b)
c)
d)
The left turn signal would flash faster.
The left turn signal would flash slower.
The left parking light would be slightly brighter.
The left parking light would be slightly dimmer.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
7. A technician replaced a 1157NA with a 1157A bulb.
Which is the most likely result?
a) The bulb is brighter because the 1157A candlepower is
higher.
b) The amber color of the bulb is a different shade.
c) The bulb is dimmer because the 1157A candlepower is
lower.
d) Both b and c would occur.
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
8. A customer complained that every time he turned
on his vehicle’s lights, the left-side turn signal
indicator light on the dash remained on. The most
likely cause is _____.
a) A poor ground to the parking light (or taillight) bulb on
the left side
b) A poor ground to the parking light (or taillight) bulb on
the right side, causing current to flow to the left-side
lights
c) A defective (open) parking light (or taillight) bulb on the
left side
d) Both a and c
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
9. A defective taillight or front park light bulb could
cause _____.
a) The turn signal indicator on the dash to light when the
lights are turned on
b) The dash lights to come on when the brake lightS are on
c) The lights-on warning chime to sound if the brake pedal
is depressed
d) All of the above
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
CHAPTER QUIZ
10. A defective brake switch could prevent
proper operation of the _____.
a)
b)
c)
d)
Cruise control
ABS brakes
Shift interlock
All of the above
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458
END
Automotive Electricity and Electronics, 2/e
By James D Halderman
© 2009 Pearson Education, Inc.
Pearson Prentice Hall - Upper Saddle River, NJ 07458