Before using your DMM plug the two probes into their appropriate places on the meter. The black probe will plug into the common port labeled “COM.” The red probe will plug into the “VΩµmA” port for most testing.
This can be illustrated with this math formula: Force = Pressure x Area.So if we were to push liquid at 1,000 psi into a cylinder with an end area of 2 square inches we would produce 2,000 pounds of force. If we were to enlarge the end area by using a larger diameter hydraulic cylinder with a 4 square inch end area, we would produce 4,000 pounds of force. Since the displacement of the larger cylinder will be greater, our cylinder will move slower but with greater force. Like all other forms of mechanical advantage, we trade speed for power.
A great feature of many DMM’s is the continuity setting. The continuity function measures resistance, and if there is a complete connection the meter will give an audible beep. If there is no continuity your DMM will show “OL” on the display meaning there is an open line. You can use this to test for electrical shorts in wiring or components. I commonly use this function to quickly test for shorted ignition switches and ignition coils.
The accessory circuit consists of your battery, ignition switch, a STSP switch and accessories such as an electric PTO, Headlights, Taillights, etc. When your ignition switch is in the “run” position your accessory terminal is energized by the battery. Power then runs from the “A” or accessory terminal to a STSP (Single Throw Single Position) switch. This switch is wired in-series and is a way to connect and disconnect power to your accessory such as your headlights. Your headlights are then wired to the STSP light switch and are wired in parallel to each other. This means two wires will come from your light switch and connect to each headlight individually. Two ground wires will also come off each headlight individually and connect to the common ground. If you were to wire your headlights in series each headlight will only use 6 volts rather than 12 and the brightness will be diminished.