Electrical System Diagnosis I

Question 1

Which of the following devices can be used to prevent overheating damage to electronic components while soldering? a) soldering pick b) desoldering bulb c) soldering gun d) heat sink

Answer 1

d) heat sink

Question 2

When would you use an analog meter as a diagnostic tool? a) on computer circuits b) when testing start draw on a vehicle c) when testing voltage output of a sensor d) to test an air bag circuit

Answer 2

b) when testing start draw in a vehicle

Question 3

A test light provides a quick way of testing a circuit for: a) amperage draw in battery testing b) power or continuity c) resistance of light bulbs d) voltage drops in the charging system

Answer 3

b) power or continuity

Question 4

Which of the following is not a method of protecting a conductor from corrosion? a) heat shrink tubing b) liquid tape c) flux d) electrical tape

Answer 4

c) flux

Question 5

A wire has come loose from an automotive component. Technician A says the tip of the soldering gun should be tinned before the wire is soldered. Technician B says that the wire and the component lead should be preheated before melting solder onto the joint. Who is right? a) Technician A b) Technician B c) both Technician A and Technician B d) neither Technician A nor Technician B

Answer 5

c) both Technician A and Technician B

Question 6

A vehicle keeps blowing the fuse for the tail lights. Technician A says that installing a higher amperage fuse than indicated in the specifications will correct the problem. Technician B says installing a higher amperage fuse than indicated in the specifications may cause damage to the wiring harness and components. Who is right? a) Technician A b) Technician B c) both Technician A and Technician B d) neither Technician A nor Technician B

Answer 6

b) Technician B

Question 7

You are testing a light circuit in which the bulb is dim. When a voltmeter is connected across the light switch, you see a reading of 2 V. The battery tested okay, as it had a reading of 12 V (fig 44). What could be the reason the bulb is dim?

a) the circuit is okay
b) the gorund has poor connection
c) there is high resistance in the light swtich
d) all of the above

Answer 7

c) there is high resistance in the light switch

Question 8

The current flow (amperage) needs to be checked in a heater fan circuit. Technician A is going to connect a digital ammeter in parallel with the fan circuit. Technician B has conencted a digital voltmeter in series with the fan circuit. Who is right?

a) Technician A
b) Technician B
c) both Technician A and Technician B
d) neither Technician A nor Technician B

Answer 8

d) neither Technician A nor Technician B

Question 9

You are going to test a computer circuit that is part of the fuel injection system. What would be the best instrument to use?

a) an analog ammeter
b) a self-powered test light
c) a vehicle-powered test light
d) a digital test light

Answer 9

d) a digital test light

Question 10

ESD (electrostatic discharge) can damage solid state components when you are handling these devices because:

a) your body can store a very high voltage charge
b) your body can store a very high amperage charge
c) of lightening strikes
d) all of the above

Answer 10

a) your body can store a very high voltage charge

Question 11

A technician is working on an electric fuel pump circuit and the pump does not run. When a jump wire is ocnnected to energize the fuel pump relay coil, the pump runs. What problem would this indicate?

a) the relay is bad
b) the relay ground is bad
c) there is no power to the coil
d) the relay coil is open

Answer 11

c) there is no power to the coil

Question 12

There is a discussion between two technicians about wirign harness and terminal repairs. Technician A thinks that acid core solder would work best for electrical repairs. Technician B says that there should be sealant showing at each end of a crimp and seal connector after heating. Who is right?

a) Technician A
b) Technician B
c) both Technician A and Technician B
d) neither Technician A nor Technician B

Answer 12

b) Technician B

Question 13

A customer brings a vehicle into a shop becasue there are no dash lights. Then technician checks the fuses and the bulbs and they are good. A voltmeter test of the printed circuit indicates 12.2 V. The technician then does a voltage drop test on teh ground side and there is a voltage reading of 12.2 V. What is wrong with this circuit?

a) the circuit is okay
b) the light switch is open
c) there is a open on the ground side
d) the circuit has high resistance as the voltage is low

Answer 13

c) there is a open on the ground side

Question 14

Two technicians suspect that the vehicle they are workign on has a grounded circuit. Technician A says that if there is a short-to-ground on the ground side of the component, but before a grounding switch, the component will not turn off. Technician B says that if a fuse blows as soon as it is installed, this indicated a short-to-ground. Who is right?

a) Technician A
b) Technician B
c) both Technician A and Technician B
d) neither Technician A nor Technician B

Answer 14

c) both Technician A and Technician B

Question 15

Two technicians are talkign about the results of a short between conductors (copper to copper). Technician A thinks that if there is a short inside a motor the resistance will increase and the motor will not operate. Technician B thinks that is there is a short between the tail light and brake light, neither circuit will operate. Who is right?

a) Technician A
b) Technician B
c) both Technician A and Technician B
d) neither Technician A nor Technician B

Answer 15

d) neither Technician A nor Technician B

Question 16

The proper method to test a potentiometer in a completed circuit would be to:

a) pierce the wires and connect a voltmeter
b) connect jumper wires into the circuit and test voltage
c) use jumper wires and connect an ohmmeter
d) do all of the above

Answer 16

b) connect jumper wires into the circuit and test voltage

Question 17

When splicing copper wire using a splicing clip, what four (4) steps would you takes?

Answer 17

a) strip wire
b) crimp on clip
c) solder
d) tape

Question 18

What four (4) precautions should a technician take to help prevent ESD damage to electronic components?

Answer 18

a) use grounded wrist strap
b) do not touch terminals
c) ground package before opening
d) connect test equipment ground lead first

Question 19

When doing circuit diagnostics to check for resistance, Technician A connected an ohmmeter to measure resistance of a component before disconnecting it from the circuit. Technician B is using a voltmeter to measure voltage drop, as the resistance of components is realted to the voltage drop. Who is correct?

a) Technician A
b) Technician B
c) both Technician A and Technician B
d) neither Technician A nor Technician B

Answer 19

b) Technician B