How do I work out why there is no sound at all from one of my speakers. I have switched them and it is definitely the speaker

Since all the speakers are the same age and have been subjected to the same conditions that the failed ones have, most definitely replace them all.

hi

sounds like a electrical problem

i would take it in for a free quote to identify the problem

there is definitely a loose connection or loom


cheers

all speakers r connected to the same wires on the radio
If left/right balance and front/rear fader work properly
and sound is coming out it is likely (but not definite) radio is ok and speaker wiring is the issue.
HOWEVER, if it sounds the same on both left and right, it could be the radio. It is unlikely both sides have the same issue at the same time without it being in the radio.
The only way to verify it to disconnect the speaker and substitute a known good speaker.
So back to troubleshooting.

Have someone check the plug ins on the speakers with a test light for power.If they show to have power, then the speakers are probably bad.make sure the car s ignition switch is in the on /acc mode with the radio on.

direct short take to specialist

Check the speakers if they work. Connect the speaker terminals using a short wire to a 1.5 volt battery (AA or any dry cell batter) and listen if there's a thumping sound when the wires are connected to the battery terminals. If there's no sound, your speakers are busted. If there's a sound, check if the wires are okay. Use the same method with the battery with the wires from the back of your stereo. Make a small cut on the wire and attach the short wires you used earlier.

switch wires around at speaker ... your polarity is backwards

Sounds like you speaker is blown, open and replace or switch speakers if still happening then radio is damaged.

If you have definitely ruled out interference from the radio/amplifier, scratching sounds would come from dust between the voice coil and the magnet. You may be lucky and be able to blow it out with air once the speakers have been removed, but normally this calls for replacement of the speakers.

You should probably take out the stereo and check the cable connections. If it has been taken out recently and put back in wrong a wire might have been pinched blocking power going to speaker or the wire is shorting out.You might just even have a cable that got burned up somehow. Mike.