Lights
What color code is used for the brake light circuit in a truck trailer electrical connector?
red
Most automotive wiring is made from?
strands of copper covered by insulating plastic
What is the common metal in fuses?
Tin
What type of filament is used in a halogen headlight?
tungsten
How many contacts are in a typical tractor-to-trailer electrical connector?
seven
Blade fuses have been used since when?
Used since 1977
When talking about wires what does larger wire diameter =?
smaller AWG number
What amperage has the color Red?
10 Amps
What is the best way to explain the construction of a halogen headlamp element?
tungsten filament encased in a quartz envelope
Battery cables are usually what size in an automotive systems
4 gauge or larger
In a standard SAE relay, which of the following is normally open (NO)?
5
What is the difference between a wire and a cable?
Wire – a conductor smaller than 4 gauge
Cable – a conductor 4 gauge or larger
What cause a circuit beaker to trip?
two different metals (bimetallic strip)
How much voltage is required to sustain the arc in a typical HID headlamp assembly?
around 85 volts
Which of the following governs highway truck exterior lighting standards in North American trucks?
FMVSS 108
Which of the following would be used to switch turn lights on a truck chassis?
stalk switch
Fusible links are what size wire smaller than the circuit wire?
A fusible link is 4 AWG wire sizes smaller than the circuit it is protecting
How is the maximum fuse rating determined for a circuit?
A maximum anticipated current flow in a circuit should be approximately 80% of the fuse rating for that circuit
What type of headlight fires an arc through gas to produce light energy?
HID
What is the maximum acceptable total voltage drop across all of the terminals and cables on the insulated side of a cranking circuit?
0.5 volts
Technician A says that a disadvantage of using LEDs as stoplights is that when the
circuit is switched on, they illuminate at a slower speed than incandescent bulbs.
Technician B says that xenon headlamps are a disadvantage in trucks because they
have a shorter service life than halogen bulbs. Who is correct?
neither A nor B
Technician A says that HID headlamps consume more electrical power than
equivalent halogen headlamps. Technician B says that HID headlamps are brighter
and their blue light is more similar to natural sunlight than that of halogen lamps.
Who is correct?
Technician B only
The headlights on a truck with electromechanical controls and circuit breaker
protection continuously illuminates for a short period and then cut out. Technician A
says that if the circuit breaker is a type 1, replacing it with a type 2 should repair the
problem. Technician B says that the problem is likely caused by a malfunction in a
type-2 circuit breaker. Who is correct?
neither A nor B
What are two ways a headlamp dimmer switch work?
switches headlamps between separate low- and high-beam circuits
applies resistance to the headlamps to reduce brightness
Technician A says that on a standard SAE relay, terminal 3 is always the common
terminal. Technician B says that in a standard SAE relay, the coil circuit must be
energized to close the normally open 5 terminal. Who is correct?
both A and B