DFFT Electrical Systems

Question 1

A vehicle's battery warning light stays on after starting the engine. What is the most likely cause?

Accepted Answer

The alternator is not charging the battery

Answer

The battery has a dead cell and needs replacement

Answer

A blown fuse in the charging circuit

Answer

The battery terminals are loose

Question 2

A vehicle's starter motor clicks once but does not crank the engine. What is the most likely cause?

Accepted Answer

A discharged or faulty battery with insufficient current

Answer

A seized engine preventing cranking

Answer

A blown main fuse in the starter circuit

Answer

A faulty starter solenoid contact plate

Question 3

All interior lights and accessories are dim and the engine cranks slowly. What does this indicate?

Accepted Answer

A weak or discharged battery

Answer

A faulty ignition switch

Answer

A short circuit in the accessory wiring

Answer

A blown alternator fuse

Question 4

A fuse repeatedly blows for the same circuit. What does this indicate?

Accepted Answer

A short circuit or overload in that circuit

Answer

The fuse has the wrong amperage rating installed

Answer

A faulty relay in the circuit

Answer

The battery voltage is too high

Question 5

A vehicle has an intermittent no-start condition with no fault codes stored. What should be checked first?

Accepted Answer

Battery terminals, ground connections, and wiring harness connectors

Answer

Engine compression on all cylinders

Answer

Fuel injector pulse width at the PCM

Answer

Camshaft and crankshaft sensor air gaps

Question 6

What tool is used to measure the voltage drop across an electrical connection or component under load?

Accepted Answer

A digital multimeter set to DC volts

Answer

An ohmmeter to measure resistance

Answer

An ammeter in series with the circuit

Answer

An oscilloscope to measure frequency