Deck 9: Lighting Systems

Question 1

Marker lamps are located on the sides of the truck or trailer.

Answer 1

True

Question 2

The center pin of a green-colored SAE J560 7-way trailer receptacle is the trailer ABS power supply.

Answer 2

True

Question 3

Referring to the figure shown below, a disconnected turn signal switch electrical connector would prevent the park lamps from illuminating with the park light switch closed.

Answer 3

False

Question 4

Referring to the figure shown below, a burned out left rear turn signal lamp filament could cause the left front turn signal to not illuminate at all with the turn signal switch in the left turn position.

Question 5

Referring to the following figure, an internal short circuit between the right rear lamp filaments may cause the front lamps to illuminate when the stop light switch is closed even though the park light switch is open.

Question 6

The clearance lamps are the three lamps at the highest point of the tractor or trailer.

Question 7

LED lamps draw considerably more current than an equivalent incandescent lamp.

Question 8

The trailer lighting is typically designed to be grounded through the fifth-wheel.

Question 9

Air brake stop lamp switches are typically normally-closed mechanically-actuated switches that detect the movement of the foot valve.

Question 10

The hazard lamps (four-ways) always have priority over the stop lamps (hazard lamps override the stop lamps).

Question 11

One low-beam headlamp has burned out on a truck. What is the reason that the other low-beam headlamp is unaffected?

A) The low-beam headlamps are wired in series.
B) The low-beam headlamps are wired in parallel.
C) The high-beam filament provides an alternate path for current resulting in a backfeed.
D) Kirchhoff's current law

Question 12

Technician A says that an open ground circuit for a dual-filament lamp always causes the lamp to not illuminate. Technician B says that amber-colored stop lamp lenses should be used at the rear of the truck if the truck has separate stop/turn lamps. Who is correct?

A) A only
B) B only
C) Both A and B
D) Neither A nor B

Question 13

Referring to the figure shown below, which failure could cause the right rear stop lamp to not illuminate with the stop light switch closed yet all other lamps still illuminate correctly?

A) Defective stop light switch
B) Shorted to ground circuit between terminal 3 of the turn signal switch and the right rear lamp
C) Open ground for the right rear lamp
D) Open circuit between terminal 3 of the turn signal switch and the right rear lamp

Question 14

Referring to the following figure, technician A says that a shorted to ground circuit between the park light switch and the right front park lamp would likely cause all park lamps shown to not illuminate. Technician B says that if the fuses supplying the stop light switch and the turn signal flasher are both blown, this most likely indicates a short to ground between terminal 4 and the left front lamp or between terminal 6 and the right front lamp. Who is correct?

A) A only
B) B only
C) Both A and B
D) Neither A nor B

Question 15

The reason for incandescent lamp surge current when initially switched on is attributed to__________.

A) Lenz's law
B) CEMF
C) the positive temperature coefficient of tungsten
D) the negative temperature coefficient of tungsten

Question 16

Technician A says that adding additional marker lamps to a trailer requires a larger circuit breaker to be installed in the tractor to adequately protect the existing wiring. Technician B says that it is always best to connect the black and brown colored trailer wires together so that a short to ground in the trailer wiring will still permit some of the trailer running lamps to illuminate. Who is correct?

A) A only
B) B only
C) Both A and B
D) Neither A nor B

Question 17

Which of the following is a true statement?

A) It is ok to touch a halogen lamp bulb provided you have clean hands.
B) Front turn signals may be red in color in North America.
C) Back up lamps are required on all trailers in North America.
D) Conspicuity refers to reflective material.

Question 18

Technician A says that instrument panel illumination may be controlled by a rheostat. Technician B says that instrument panel illumination may be controlled by pulse width modulation. Who is correct?

A) A only
B) B only
C) Both A and B
D) Neither A nor B

Question 19

The dome lamps will not switch off when both doors are closed on a truck. Which of the following could be the cause?

A) Shorted to ground circuit between the dome lamp and the door switches
B) Left side door switch is remaining closed with door closed
C) Right side door switch is remaining closed with door closed
D) All of the above could cause this problem.

Question 20

The headlamps and other incandescent lamps have a history of burning out repeatedly on a truck a short time after being replaced. Which of the following could be the cause?

A) Poor fifth wheel ground
B) Batteries with too high of a CCA have been installed
C) Low charging system voltage
D) High charging system voltage