The multimeter combines multiple electrical diagnosis functions into one portable unit. Technicians can use this tool for a variety of applications, including measuring voltage drop, continuity checks, diode checks, capacity checks, and more.

In the video above, Purkeys National Truck & Fleet Representative, Larry Rambeaux, demonstrates how to conduct a diode check using a multimeter. A diode is an electrical component that allows current to flow in one direction, but not the other.

To perform a diode check, technicians need to set their multimeter dial to the correct setting, then press the mode button until the symbol for a diode is visible on the LCD screen.

If a technician connects the multimeter leads to the diode in the opposite direction of the flow of current, they will get a reading of OL. If the multimeter leads are properly connected, the reading will show the voltage drop across the diode.

An open diode will read OL regardless of which direction the multimeter leads are connected. If the multimeter reads multiple zeros, the diode is shorted, which allows current to flow in either direction.

Diodes can be used in many different types of circuits. It is important for technicians to know how to properly use this function to understand the diode’s function in the circuit.

Are you dealing with battery issues? Are you looking for advice? We welcome your comments and questions below.

Learn more about multimeters and how to use them by watching our most recent webinar, Multimeter Training and Tips.

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