Current Clamp

It clamps around one wire. Low-amp clamps measure small currents. It works with multimeters or oscilloscopes. Clamps are useful for checking fuel pump current, starter current and parasitic drain. The current waveform of a fuel pump can show worn commutator segments. Clamps come in high-current versions for starters and low-current versions for small loads. For accurate readings, keep the clamp jaws clean and close them fully around the wire.

It senses the magnetic field around the wire.

Zero it before measuring. Clamp one wire only.