To measure parasitic current drain, what unit must the DMM display?

To accurately measure parasitic current drain in automotive or electronic systems, the digital multimeter (DMM) must display current in milliamps. Parasitic drain typically refers to the small amount of electrical current that continues to flow through a system when it is supposed to be off, such as when a vehicle is not in use.

In this context, measuring in milliamps is essential because parasitic drains are often very low. The currents can range from a few milliamps to microamps, but using the milliamp setting provides the precision needed for most automotive systems.

If the DMM were set to amps, it might not provide the sensitivity required to capture the small current readings accurately, as the scale would not allow for fine resolution of low draws. Similarly, measuring in volts or microamps would not be appropriate or practical for testing the small current draw typically expected in parasitic drain scenarios, as the focus is on how much current is being drawn, not the voltage levels or excessively low microamp readings which are often unsuitable for diagnosing parasitic draws in most situations.