Time Needed: 10 minutes, Difficulty: None existent, Cost: $10-$50
Your dashboard’s lights have gone out. There’s a weird buzz coming from your radio. Your automatic wipers have gone on the fritz. Or, just maybe, every electrical component in your car refuses to start. Where do you start diagnosing the issue? With a multimeter, of course!
A multimeter is a small electrical device that measures a host of electrical variables such as volts, current, and resistance, and can help diagnose exactly what’s wrong with a certain electrical component. To use one, however, can seem complicated and potentially dangerous for the novice. It doesn’t have to be. Follow along and let Car Bibles’ crack editors walk you through exactly how to use a multimeter.
The Safety Brief
We want for you to exit the garage with all the fingers you went in with. There’s no need for safety to come third, make it first. To ensure your skin stays unblemished and your bones intact, you’ll want to use a good, non-conductive mechanics glove. You definitely don’t want to get shocked.
The Tools & Parts You Need
A trip to the auto parts store or waiting on your porch for Amazon can be a time-suck. Don’t spend the day twiddling your thumbs waiting for a package or driving to and from the store.
Prepare for your jobs by researching what you need and buying the proper tools ahead of time. To follow along today, you’ll need the following:
Here’s how to use a multimeter to diagnose what’s wrong with your vehicle’s electrical components.
1. Grab Your Multimeter
There will be multiple settings on the multimeter; volts, resistance, and current are the most common settings you can test for. These settings are meant to help determine exactly what’s the issue with your vehicle’s electrical components, such as a relay, a battery, or other electrical component. Here’s what they mean.
Measures how much electricity is getting pushed into a circuit from the battery.
Resistance is how difficult it is for electricity to flow through a circuit.
Current is how much electricity is flowing through the circuit from the battery.
You’ll also see symbols denoting Alternating Current and Direct Current, which you’ll use depending on the type of current used in each part’s particular circuit. And lastly, there’s a Continuity Check symbol, which looks like the WiFi symbol, denoting whether or not a circuit is connected.
Lastly, there are two wires connected to probes. They are:
- Red Probe/Lead
The red probe/lead is meant for the positive electrical output.
- Black Probe/Lead
The black probe/lead is meant for the negative electrical output or ground.
2. Using the Probes
Your settings will depend on what you’re testing for, but the process remains the same. Attach the multimeter’s leads to their corresponding electrical connections. Adjust the multimeter to the predetermined settings of either volt, current, or resistance.
Adjust the multimeter’s specific volt, current, and resistance settings to the specific setting to what you’re testing, i.e. 20v, 200v, or 1000v. Let the multimeter do its job and see what’s what! And there you have it, how to use a multimeter.
Your Questions, Our Answers on Multimeters
Car Bibles’ answers all your burning questions.
Q: What Should You Not Do With a Multimeter?
A: If the leads are broken, damaged, or corroded, don’t use them.
Q: Can a Multimeter Kill You?
A: Are you planning on sticking one of the probes into your ear socket and the other directly to the car’s battery? Because that’s really the only way.
Q: Can a Multimeter Explode?
A: If you use a meter or probe/lead that isn’t rated for your specified use, then yes, it can. It is, however, extremely uncommon.
Video Tutorial on Multimeters
Car Bibles’ editors understand that not everyone is a text-based learner. For those kinesthetic people out there, we have your back with a video showing you exactly how to use a multimeter. We pulled it from one of our most trusted sources and it’s a great additional resource.
Our Favored Multimeter Products
You can buy electrical tools at almost every auto parts and home improvement store. As well as online stores like Amazon. You have a sea of options to select from. Our choice to help us get through weird electrical glitches, however, remains the humble OBD2 scanner. Here are a few of our favorite options.
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