TAKING READINGS WITH A MILLIOHMMETER In the automotive service world, milliohmmeters are most commonly used to measure and compare phase-to-phase resistances of three-phase stator windings, as used in hybrid, plug-in hybrid, and electric vehicles. Such measurements can range from a few milliohms to several hundred milliohms. Milliohmmeter leads are typically equipped with alligator-type leads, with a twist: rather than gaining a good connection by biting into the test point, the quality of the electrical connection to the test point is often more dependent on the amount of contact area between the leads' jaws and the test point. Quality milliohmmeter leads are typically goldplated to inhibit corrosion and reduce the Pico MT03 is being used to measure phase-to-phase drive motor resistances on a 2013 Toyota RAV4EV. Photo courtesy of Jack Rosebro likelihood of unwanted resistance in the leads themselves. Sometimes it takes a bit of fiddling to get a stable reading; cleaning the stator winding terminal ends with isopropyl alcohol may help. It may also help to twist the leads as with communication For more information visit VehicleServicePros.com/10094540 2312PTEN_Pico Technology.indd 1 11/8/23 10:13 AM VehicleServicePros.com DECEMBER 2023 11https://www.picoauto.com/library/picoscope/picoscope-guided-tests?A1465&utm_source=A1465&utm_medium=Online&utm_campaign=PTENHalfPg http://www.VehicleServicePros.com/10094540 http://www.VehicleServicePros.com