Technician A looks for engine speed (RPM) when cranking an engine that will not start. Technician B says that a problem in the primary circuit could make the tachometer not work. Which technician is correct?

Question

Quizplus · Accepted Answer

Both technicians are correct. Technician A checks engine speed (RPM) during cranking to diagnose starting issues, which is a valid diagnostic step. Technician B is correct that a problem in the primary ignition circuit could prevent the tachometer from working, as the tachometer often receives its signal from the ignition system.

Technician a Looks for Engine Speed (RPM) When Cranking an Engine