Rapidly diagnose electrical faults
Diagnosing automotive electrical problems is never easy. But starting at the root of the problem might be a good start. Finding out if a circuit has power can help rule out other problems. A circuit tester is a handy tool that can indicate if a circuit has power. Here's how to use a circuit tester and how to find the right one for your needs.
What is a circuit tester?
A circuit tester is nothing more than a portable circuit designed to be easily and temporarily connected to power and ground. It helps you see (or hear) if there is power in the wires. There are several circuit testers available for different types of diagnostic needs. The most basic and common type of circuit tester looks like a screwdriver with a pointed tip. There is a light source (bulb or LED) inside the handle. There will be a wire with some kind of clamp on the end of the handle for temporary connection to the battery. It is a simple tool, but well worth having when the need arises.
Learn About Circuit Testers
A simple circuit tester is simple to use. Get familiar with the tool by performing a simple test on a battery. Connect the circuit tester's ground clamp to the negative terminal of the vehicle's battery. Now touch the circuit tester's probe tip to the positive battery terminal. The light on the circuit tester's handle should light up. You will see the following when current flows through the circuit you are testing.
Circuit Tester Type
There are many different types of circuit testers, ranging from simple to complex. Here are a few you may encounter in the automotive industry.
Standard circuit tester——This is the most basic tester. A probe, a light, and a wire. Nothing special, and it has barely changed in decades. They are inexpensive and a must-have in your toolbox.
Multifunctional circuit tester——
This circuit tester not only tests the current, but it can also indicate if a connection is hot or grounded. You'll usually need to plug it into its own power source or connect it to a battery. It's a bit more advanced than a basic circuit tester and actually uses some electronic circuitry to work its magic.
Circuit testing pliers——
Sometimes it's difficult to get a circuit test probe into a tight space. For tight work spaces, you can use circuit test pliers. These special pliers have a sharp needle in the jaws that gently pierces the outer insulation of the wire for testing. There's also a normal pointed probe that flips up for normal circuit testing use.
Digital circuit tester——
Now you've entered the high-tech realm of circuit testers. Digital circuit testers can test components, read voltage levels, check continuity, check grounding, test relays, and more. Some even upgrade to full kits with circuit tracing capabilities. While they're pricey, if you spend a lot of time hunting for electrical faults, a digital circuit tester may be the way to go.