Run the wires out of the amplifier – You can connect these wires to a 9-volt battery and listen to the sound produced. In some cases it will be necessary to unscrew the car speaker. Unless you have experience with auto mechanics, do not remove the wires.
Examine the car speaker – To examine the car speaker, you will need to remove the cover and connect the wires to a 9-volt battery. If the cone moves, it’s a connection issue and not the speaker’s.
Test for resistance – With your multimeter, you can test the resistance of your car’s speaker. Remember to put it in Ohmmeter mode and turn off the speakers. Then place the tip of the device on the terminals of the car speaker, i.e. where the wires are soldered.
If the value is 1 ohm, your car speaker is in good condition. Otherwise, if you get an infinite number, it means that it is completely broken.
To test the amps, the multimeter will need to be connected to the fuse box. This allows you to check if the fault is coming from the fuse or the capacitor. If there is a beep, the capacitor is faulty and the amplifier will need to be replaced. Otherwise, the fuse itself will blow.