On/off push buttonpush to turn the EEDM503C on and off. Ohm function measure ohms to determine resistance of a coil or spark plug wire. Continuity buzzertest continuity of fuses, fusible links, components and circuits. Diode testuse the diode function to test the diode pack on a typical alternator. DC ampsmeasure DC current to determine the presence of a parasitic load. Measure current draw of branch circuits. Data-H (Data hold)lock reading on the display in hard to read locations or for future reference. DC VOLTSUse DC voltage to verify if the proper voltage level is arriving at a sensor of circuit. AC Voltsmeasure AC voltage signals on digital MAF sensors, wheel speed sensors and vehicle speed sensors. AC ampsmeasure the current draw of AC powered equipment in the shop. Tilt standis built-in into the instrument housing. Separate fuse/battery compartmenteasily removed for battery/fuse replacement. Fuses are labeled with replacement number.