Hey, I saw a post of yours where you toasted a driver testing it. Here's how and why to use a multimeter:
Current, measure in series. Current through things in series is equal; so current through a battery and incandescent bulb and your tester will be the same. When measuring huge currents, thin test leads will affect your results.
Voltage, measure in parallel (across the load or terminals). Think of a circuit diagram, you'll see the voltage drop of a component when you measure in series.
Resistance, measure across the device. I usually measure resistance without power running through it because I hate squinting around bright lights - but it won't affect anything.
Good luck with the bike light!
Current, measure in series. Current through things in series is equal; so current through a battery and incandescent bulb and your tester will be the same. When measuring huge currents, thin test leads will affect your results.
Voltage, measure in parallel (across the load or terminals). Think of a circuit diagram, you'll see the voltage drop of a component when you measure in series.
Resistance, measure across the device. I usually measure resistance without power running through it because I hate squinting around bright lights - but it won't affect anything.
Good luck with the bike light!