B2U2 Engine Direct Current Electrical System Flashcards
What is the purpose of the starter motor?
Changes electrical energy into mechanical energy to rotate the engine for startup.
What two functions does the starter solenoid accomplish?
First, it moves the mechanical drive to engage the pinion gear into the flywheel. Second, it closes a set of
contacts to energize the starter motor once the pinion gear is meshed with the flywheel.
What occurs when the coil of a crank relay energizes?
The crank relay contacts close providing a path of current flow to the starter solenoid.
Which battery-charging alternator components turn on the alternator when voltage drops below a preset level?
Voltage regulator.
What do you inspect on a starter and a starter solenoid?
Inspect the starter solenoid terminals for corrosion, inspect the starter and starter solenoid for signs of damage and security of mounting bolts, and look for discoloration or other signs of overheating of the starter motor and starter solenoid.
What are the first two things you do when replacing a starter motor and solenoid?
Disconnect the negative cable from the battery terminal and tag and disconnect the electrical leads from the starter motor.
Why must you ensure you keep correct polarity when reinstalling a starter motor?
You may damage the battery and other electrical component.
What can happen if a charging rate is too high?
You can damage the battery.
What must you do before working on a battery-charging alternator?
Disconnect the negative battery cable before working on the battery-charging alternator.
What type of mixture are the spongy lead negative plates and lead peroxide positive plates of a lead-acid cell immersed in?
A diluted solution of 30 percent sulfuric acid and 70 percent distilled water.
What types of batteries are sealed making it impossible to service the electrolyte?
(1) Maintenance free.
(2) Absorbent glass mat.
(3) Gel cell.
How much does the specific gravity of a lead acid battery electrolyte change with temperature?
.004 for every 10 degrees in temperature change.
If the level of a lead acid battery is low, what should you add to the electrolyte to return it to the proper level?
Distilled water
What are the steps in the troubleshooting process?
(1) Perform an operational check.
(2) Analyze the malfunction.
(3) Locate the malfunction.
(4) Perform corrective action.
(5) Perform an operational check.
What are the electrical malfunction symptoms for an open?
(1) Circuit is inoperative.
(2) Protective device does not activate.
(3) Indicator lamps do not illuminate.
What are the electrical malfunction symptoms of a direct short?
(1) An inoperative circuit
(2) The protective device actuated.