Current is a critical component of any electrical system.
In basic terms, current is the flow of electricity. It is quantified in amperage, with “amps” being the unit of measure.
It’s important to note that current isn’t the same thing as voltage, so don’t make the mistake of using those terms interchangeably. The proper voltage and current however, are both vital to ensuring that your electrical components work correctly.
Unlike checking voltage, which can be as simple as touching the positive and negative multimeter probes to their corresponding +/- terminals on the battery, motor, etc., testing current requires the multimeter to be hooked-up in series with the circuit.
“In series” means that the meter is installed in-line with the electrical circuit. That also means that you’ll have to break the circuit temporarily, in order to insert the meter’s probes.
To compound matters, using a multimeter can be a confusing process for those without much experience working with electronics.
That’s why this video from the fine folks over at ACDelco is so handy.
It takes a 101-style approach to teaching you how to test electrical current, including some basic electrical theory, multimeter setup, and fundamental diagnostic procedures.
It’s about eight minutes long, so it’s packed with pointers. The video is a good watch—even if you’re competent around basic electrical circuits.