I watched an instructional video the other day where the guy kept palming his gauge manifold and CRANKING down on the valves when he closed them. I've seen techs use channel locks—and even vise grips—to tighten down their gauges “just in case” when they have a hard time finding a leak or a vacuum that […]

If you don't use a scale every time you add or remove refrigerant, I suggest you begin doing so immediately, if not sooner. Weighing in while charging is fairly obvious, and it's useful so you can keep track of what you are using and how much to charge a customer. When you have a system […]

In a series circuit (loads connected in a row end to end), it's easy to calculate total circuit resistance because you simply add up all the resistances to get the total. In a parallel circuit, the voltage is the same across all the loads; the amperage is simply added up, but the resistance is a […]