When your car doesn’t start, often the battery is the culprit. Unfortunately, most vehicle owners do not check their battery until it fails. As preventative maintenance, the suggested best practice is ...

This video covers the essential steps to properly test a car's alternator and diagnose common alternator issues. The guide ...

You can use them to test for voltage drop at various circuits, blown fuses, current draws, heating elements, and to verify bad cable connections. The most common task is checking pedestal voltage.

If you’re using a digital multimeter, set the dial to DC voltage. Next, take your multimeter’s black lead to the negative battery terminal and the red lead to the positive terminal.

If your power supply's voltage is 125 volts, switch your multimeter to read a range of 100-200 volts.

The multimeter should read between 11 and 12 volts. If it's too high or too low, the power supply is failing and needs to be replaced. Test pin 12 as well. Test pins 4, 8, 9, 19 and 20 for 5 volts.

Volts are the pressure of the water (psi), amps are the number of gallons per minute (volume), and ohms are anything that limit the flow. To measure electrical energy, a multimeter has two wire leads.