It's a must-have for any toolbox—but there's a learning curve involved. Learn how to use a multimeter for all of your electrical testing needs.

If your power supply has an on/off switch, turn the power supply on. Switch your multimeter to the range that is appropriate for reading the voltage from your power supply.

Car batteries don't just die. Something is sucking up all its power. A parasitic draw test helps you find out which part is to blame.

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