Home › CDL Practice Tests › General Knowledge Questions › Question 367
What is the voltmeter or ammeter telling you, and which reading is a warning?
- A.It shows fuel economy
- B.Any reading is acceptable while the engine runs
- C.It only matters for the radio
- D.It shows whether the charging system is supporting the electrical load; a steady discharge or voltage outside the normal range warns of alternator or battery failure ahead
Correct answer
D. It shows whether the charging system is supporting the electrical load; a steady discharge or voltage outside the normal range warns of alternator or battery failure ahead
Why
A charging system that is losing ground will strand the truck when the battery can no longer power fuel and control systems, often at night or in bad weather. Catching a discharge trend at the gauge turns a roadside failure into a planned repair.
Manual topic: Gauges - Electrical · From the General Knowledge practice bank (GK-367).