How To Maintain Your Car's Electronics Using a Multimeter

Modern cars are no longer pure mechanics the majority of cars being produced now are made up of mostly electrical components. This means that making sure the tires are at the right pressure, the oil has been changed, and the brake pads aren’t worn are not our only cause for concern. Ensuring our car's electrical components are safe and working is just as essential. 

We can do this in a few ways but the most accurate form of checking is by using a multimeter, these indicate the level of voltage reaching any component and look at the resistance of the circuit. 

What Is a Multimeter? 

There are many different meters you can purchase that are designed specifically for sessions of the car. However, one of the most useful bits of kit is a multimeter. As the name suggests, they are meters that will provide many different readings for several different functions when it comes to checking car electronics. 

Direct current (DC) is what’s used on cars and a multimeter can check the voltage, the current, and the resistance readings in a car. Some even contain some extra functions that are helpful when checking over your vehicle. There are plenty to choose from when looking at multimeters and the price point will very much depend on how many features you’re after. Having something in the toolbox that covers all bases will be hugely beneficial in the long run. 

How Do You Use a Multimeter?

Much like anything new, it might take a little bit of time to get used to using your multimeter. Luckily, it’s not rocket science and they’re pretty easy to use. You’ll find two cables within the kit, one black, and one red. These represent negative (black) and positive (red). When using the multimeter for an amperage test then the red lead should be used in the fused port whilst most other tests will be conducted using the non-fused port. This is because your meter will blow up when using the non-fused port in conjunction with amperage tests. 

You can perform most tests with the leads on either pole and they end up being reversed then you will see a (-) symbol. It’s also used to see if there’s a circuit that is reversing polarity. The majority of meters will have a voltage limit which is fine when you’re dealing with a car, even the wall socket in your house, but if it’s anything above 230v then it’s not going to work. If you are dealing with 230v+ then you’re probably trained and have the right kit anyway. 

Check the Battery First

Usually, it’s a pretty good idea to check the battery before performing any other test. This is to make sure the battery itself is performing up to its usual standard. First, you’ll have to set the meter to the appropriate scale which is 0-20 volts. Following this, connect the leads to the battery terminals and not the lead connections. For a low charge reading, you should see a reading of around 11 volts, and for a full charge, a reading of 12 volts will be shown. 

You should suspect a fault within the battery if the reading is less than 10 volts. To check this, move the earth cable and connect it to a near point on the body of the car. Lower readings tend to mean a poor connection between the earth lead and either the body of the car or the battery terminal. 

Checking Other Components

You’ll have to be knowledgeable about cars if you want to start taking things apart to check them yourself. So throw caution to the wind before getting any major tools out. There are plenty of guides online that will be able to help you but if you’re feeling out your depth then it’s best to call in the professionals or get the car to a garage. You can check other areas like the sender unit, which is used to show the level of your petrol tank, your ignition if you are having trouble starting the car, and even high tension leads. 

Driving a vehicle that’s safe for yourself and others on the road is your duty as a road user. This means checking your car before you drive and when you arrive at your destination, especially if you’ve been on a long journey. Don’t take a chance when it comes to the health of your car, invest in some tools that can help you manage it. A multimeter won’t break the bank and can help you identify some problems that you could fix on your own.