Purkeys Electrical Tool Kit comes with a variety of useful tools to help technicians test and diagnose heavy-duty vehicle electrical systems. One of the tools in the kit is the inductive, clip-on ammeter.

Unlike a standard multimeter, the clip-on ammeter measures current through the magnetic field, generated by the current flowing through the conductor. By clipping the interlocking jaws around the wire, technicians can get an accurate measurement without breaking the circuit to take the reading.

In this video, Purkeys National Truck & Fleet Representative, Larry Rambeaux, demonstrates how easy it is to use the clip-on ammeter. Larry notes two very important things before he begins to measure: 1) the ammeter has 40 amp and 400 amp settings and 2) the arrow inside the jaws indicates which direction the current should be flowing. If technicians clip the ammeter on with the arrow facing the wrong way, it will still work, but will show a negative value.

In past videos, Purkeys’ professionals have talked about the importance of checking for parasitic loads. The ammeter is perfect for that; it can check a cable for a high load without disconnecting anything. It can also be used to check an alternator or liftgate cables; simply clip it on and see exactly how much current is flowing.

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

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