Think of this as electrical volume. Amps can be determined by taking your voltage (12 volts) and dividing it by the resistance of a load. This is illustrated with the following formula: A = V/R
The ability to detect, observe, and measure electricity is crucial when trying to understand how a tractor works and learning what you can do to fix it. The digital multi-meter is like a doctor’s stethoscope. It allows us to see the invisible force of electricity and measure how it interacts with the components in our engines and tractors. A digital multi-meter measures current (amps), voltage (volts), and resistance (ohms).
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.
Since liquids exert force equally in all directions we can multiply the force it gives by increasing the surface area in which we want the liquid to push against. Typically we apply this principle in a hydraulic cylinder. The greater the surface area at the end of the cylinder, the more force gets exerted on the moving piston.