A Multimeter can be used for different operations of a car at our home either at auto-workshop. There are 4 simple ways to use a multimeter for auto-electricians of vehicles, cars, buses to shoot anyone trouble related to them. These digital brands may be useful when you are working on a car or other related automotive work at home or workshop.
How to use a multimeter to test a car battery
When you are facing that your car battery power is running low then you may check it easily by using a multimeter
For this purpose, you have to ….safety precautions because the car and other vehicle lead battery contain chemicals which are very dangerous so you must wear safety gloves and glasses.
Now, First of all, with reference to the manual, plug out the battery cables but, stop here just check the engine if it is too hot then wait so it may be cold so then you can check it easily.
There are two terminals of battery, positive & negative terminal
Take the red probe of your multimeter to the positive terminal and block probe with a negative terminal. Before the connection of probe make sure that you are using a 20V DC for precise reading
Hold then for a few seconds and then check meter that shows your readings. It is so simple to check
If your 12v battery showing 9.6 volts to receive a charge which is not supported to run a car, you may require a new fully charged battery.
Pros Tip: A 12-volt battery that is fully charged and is not connected to the car should display readings of between 12.4V and 12.7V.
How to use a multimeter to Test a car alternator
If there is no issue with the battery then you can say that the testing alternator is a smart move.
The same as the above method, use the safety precautions
Now, Set the Multimeter to 20 volt DC
Make ensure that battery is connected and the car engine is switched off
For testing the battery, connect red to positive and black to negative as it was done in the above method
If the engine is switched off then, it shows Reading shows 12.5v to 12.8V that means there is no problem with the battery
Now, after the startup of engine multimeter readings should be between 13.8v to 14.8v that’s mean your car alternator is working perfectly.
As a result, if you quickly look the heater blower to high and turn on the headlights, you’ll notice a slight drop in voltage before the reading returns to the above range. (This is assuming that the alternator is working OK.)
Testing the wires on your speakers by using Multimeter
You have the dash open, Remove the stereo system and door panels.
The speakers are just about to be replaced but you are worried and you don’t know which is positive and which is negative.
Bring out your multimeter!
Put your stereo on with the volume low.
Set the multimeter to 20V DC.
Touch the negative probe on to one of the frame grounds. Get the speaker and put the positive probe on one of the terminals.
The one with the voltage is positive. The job is done!
Checking the ohms on your subwoofer
Nowadays most people use powerful subwoofers in their car for the purpose of entertainment.
As these subs are connected and ready to go, you must be alert. When you wish to connect the wires from the subwoofer to the amplifier, it’s essential that they are correctly wired.
Plugin both ends of the multimeter to the amp’s speaker terminals.
Set the multimeter to 200 ohms (Ω) and you can check that the ohm level of the sub tallies with the rating of the amplifier