While using a digital multimeter to diagnose electrical problems on customers’ equipment, I frequently hear the comment, “I’ve got one of those multimeter things, but I never learned how to use it.” ...

Gear-obsessed editors choose every product we review. We may earn commission if you buy from a link. Why Trust Us? A digital multimeter is an indispensable tool for testing, diagnosing, and ...

Begin by connecting pin 85 of the relay to a clean ground point on the vehicle chassis or the negative terminal of the battery. Then connect pin 86 to the ignition switch wire — this is the wire that ...