A continuity tester has a probe, which contains a battery and a light bulb, and a wire lead. The battery allows the device to generate a small electrical current, and when you touch the ends to ...

No multi-meter? For troubleshooting most household things, a continuity tester is extremely handy. And as it turns out, you can make your own from the dollar store for next to nothing.

Because different electrical circuits can have vastly different resistances, there are multiple stages of measurement on a ...