Automotive Electrical Diagnostics AUT. 149
UPDATED ACTUAL Exam Questions and
CORRECT Answers
A potentiometer [type of variable resistor] can be tested with all the following tools EXCEPT:
Test light
Voltmeter
Ohmmeter
digital lab scope - CORRECT ANSWER - Test Light
A technician is checking a circuit with excessive resistance. The current flow through the circuit
should be 10 amps, but a check with an ammeter measures only 6 amps. The technician measures
a voltage drop of 1.0 volts across the switch terminals when the circuit is turned on. What is the
resistance of the switch?
1/16 ohm
1/6 ohm
6 ohms
60 ohms - CORRECT ANSWER - 1/6 ohm
A technician is diagnosing the cause of an insufficient heat problem. He notices the fan is
working but not providing much air flow. He disconnects the fan power feed wire and connects
the fan to the battery using a fused jumper wire. The specification for the fan motor is 16 amps.
His ammeter shows 26 amps when the fan is jumped directly to the battery. What could be the
problem?
bad fan motor ground
high resistance in the fan motor wiring
,shorted wiring in the fan motor
all answers are correct - CORRECT ANSWER - Shorted Wiring in fan motor
A technician is testing a circuit that uses a ground-controlled relay to provide power to the circuit
load. With the relay installed in its socket, the control terminal of the relay is grounded by a
jumper wire; nothing happens. Technician A says check the coil input terminal for voltage.
Technician B says connect a jumper wire between battery negative and the output terminal of the
relay to check if the load is the problem. Who is correct?
A only
B only
both A and B
neither A nor B - CORRECT ANSWER - A only
A technician is testing a connector in a circuit with a voltmeter. With the power on in the circuit,
the meter reads 12 volts when the leads are placed on each side of the connector. This indicates
that the connector _____.
is shorted to ground
,is open
is good
has current flowing through it - CORRECT ANSWER - is open
All the following are lab scope adjustments EXCEPT:
trigger level
slope
trigger source
amperage level - CORRECT ANSWER - Amperage level
All the following information about the vehicle's wiring can be found in the electrical schematics
with the exception of _____.
, wire color
wire size
connector terminal designation
component location on vehicle - CORRECT ANSWER - Component Location
DMMs that can measure temperature use a _____ adapter that is placed on or near the object to
be checked.
thermometer
thermocouple
manometer
refractometer - CORRECT ANSWER - Thermocouple
Oscilloscopes are being discussed. Technician A says the vertical positions represent time.
Technician B says the horizontal positions represent voltage. Who is correct?
UPDATED ACTUAL Exam Questions and
CORRECT Answers
A potentiometer [type of variable resistor] can be tested with all the following tools EXCEPT:
Test light
Voltmeter
Ohmmeter
digital lab scope - CORRECT ANSWER - Test Light
A technician is checking a circuit with excessive resistance. The current flow through the circuit
should be 10 amps, but a check with an ammeter measures only 6 amps. The technician measures
a voltage drop of 1.0 volts across the switch terminals when the circuit is turned on. What is the
resistance of the switch?
1/16 ohm
1/6 ohm
6 ohms
60 ohms - CORRECT ANSWER - 1/6 ohm
A technician is diagnosing the cause of an insufficient heat problem. He notices the fan is
working but not providing much air flow. He disconnects the fan power feed wire and connects
the fan to the battery using a fused jumper wire. The specification for the fan motor is 16 amps.
His ammeter shows 26 amps when the fan is jumped directly to the battery. What could be the
problem?
bad fan motor ground
high resistance in the fan motor wiring
,shorted wiring in the fan motor
all answers are correct - CORRECT ANSWER - Shorted Wiring in fan motor
A technician is testing a circuit that uses a ground-controlled relay to provide power to the circuit
load. With the relay installed in its socket, the control terminal of the relay is grounded by a
jumper wire; nothing happens. Technician A says check the coil input terminal for voltage.
Technician B says connect a jumper wire between battery negative and the output terminal of the
relay to check if the load is the problem. Who is correct?
A only
B only
both A and B
neither A nor B - CORRECT ANSWER - A only
A technician is testing a connector in a circuit with a voltmeter. With the power on in the circuit,
the meter reads 12 volts when the leads are placed on each side of the connector. This indicates
that the connector _____.
is shorted to ground
,is open
is good
has current flowing through it - CORRECT ANSWER - is open
All the following are lab scope adjustments EXCEPT:
trigger level
slope
trigger source
amperage level - CORRECT ANSWER - Amperage level
All the following information about the vehicle's wiring can be found in the electrical schematics
with the exception of _____.
, wire color
wire size
connector terminal designation
component location on vehicle - CORRECT ANSWER - Component Location
DMMs that can measure temperature use a _____ adapter that is placed on or near the object to
be checked.
thermometer
thermocouple
manometer
refractometer - CORRECT ANSWER - Thermocouple
Oscilloscopes are being discussed. Technician A says the vertical positions represent time.
Technician B says the horizontal positions represent voltage. Who is correct?
