Automotive Electrical Systems: a 2021 Revision Aid

What would be the most suitable test to carry out if a battery does not charge?

• Check all the lamps have the correct rating

• Check for corrosion on the starter motor Positive connection

• Carry out an Alternator Current Output Test

• Test the Specific Gravity of the electrolyte

When conducting an alternator current output test what is the most common meter reading?

• 36 Volts

• 36 Ohms

• 36 Watts

• 36 Amps

What will cause the Specific Gravity (SG) of a battery to vary?

• The state of charge of the battery

• The internal resistance of the battery

• The relative outside air pressure

• The number of consumers switched on

If a windscreen wiper does not operate which of the following would you check first?

• The wiper blade

• The windscreen rain sensor

• The third brush in the motor

• The circuit fuse

In a 12 Volt car battery in good condition, what is the minimum cranking voltage that should be seen when tested?

• 8.7 Volts DC

• 10.5 Volts DC

• 14.5 Volts AC

• 12.36 Volts DC

Why does the battery supply a small voltage even when all circuits are switched off?

• To maintain a small working temperature in the battery

• To ensure the glow plugs are warm for enhanced cold starting in winter

• To prevent component memory loss in the radio

• To maintain constant monitoring of the Tyre Pressure Monitoring System (TPMS)

Which component in an alternator converts AC Voltage into DC Voltage?

• The regulator

• The armature

• The commutator

• The rectifier

Which electrical component contains brushes, parking cam and worm gears?

• The Alternator

• The Starter Motor

• The Wiper Motor

• The Automatic Gearbox

In an alternator, which electronic components are used to convert AC into DC?

• Diodes

• Resistors

• Transistors

• Thermistors

Where in the electrical circuit are you most likely to find a Darlington Pair?

• An ABS Reluctor Ring

• A Double-ended Wasted Spark Ignition Coil

• A Voltage Regulator

• A pre-engaged starter motor