How can I get a much louder siren

I have the exact same car and I fixed it avoiding a huge bill. I just found the siren and big fat pulled it out! It's under the boot liner with the spare tyre. I had to remove the bolts which fasten it to the side and then I unplugged it. The alarm went off like mad, has its own power source. But after I removed it, I tried the car and it wasn't immobilised and it didn't suffer in any way. Now I have no alarm but I live on a quiet country road and have my car locked up. I'd rather risk it than have the embarrassment of it going off while I'm driving!! It must have been fitted wrongly as everything I read said a factory fitted alarm will enable the immobilizer if removed but it didn't do that so, must have been all wrong anyway. I couldn't find another fix. This was drastic but it worked.

By alarm, so you mean a that you are hearing a loud siren type alarm while driving, or do you mean a light lit up in the instrument cluster / dash??

If it is a loud siren, it may be that the car was perviously fitted with an aftermarket alarm system and the alarm has a problem. There are some alarm installers that do not take in pride in their work and you can end up with a mess. These installations can cause all kinds of problems and they are the first thing I look for, and remove when there are issues.

If it is just a light in the dash that you don't understand, check out the image I uploaded below and please respond back with the shape of the light in question.


Hope this helps!

It is on a system that cannot be disabled. The siren has gone bad and needs to be replaced. Check your dealer for a new siren. The odds of finding a good one in a salvage yard are very slim.

Your Siren alarm might be faulty. Do you have any error messages on your SID display? The siren alarm located behind the driver side fender. The Siren alarm can be replaced or bypass the unit with a Tech2 scanner. A new Siren alarm is very expensive ($360+) from the dealership. However, you can get your original unit rebuilt through BBA vendor for about $85.00 with life time warranty.

Good luck

I have a Micra c+c 08, and I fixed it avoiding a huge bill. I just found the siren and big fat pulled it out! It's under the boot liner with the spare tyre. I had to remove the bolts which fasten it to the side and then I unplugged it. The alarm went off like mad, has its own power source. But after I removed it, I tried the car and it wasn't immobilised and it didn't suffer in any way. Now I have no alarm but I live on a quiet country road and have my car locked up. I'd rather risk it than have the embarrassment of it going off while I'm driving!! It must have been fitted wrongly as everything I read said a factory fitted alarm will enable the immobilizer if removed but it didn't do that so, must have been all wrong anyway. I couldn't find another fix. This was drastic but it worked.

after locking the car via key fob, few minute later siren and flashers comes on..is it the faulty siren ?

Is there power to the siren? Are the lights flashing? Can you choose to have the siren on or off? If the lights flash and there is no power to the siren it may be the controller. If you have power to the siren then make sure you have good ground at the siren even if you have to run a ground wire from it

If you need further help, I’m available over the phone at https://www.6ya.com/expert/edward_020b3320326d263d

if noise gets louder as you speed up , most likely a wheel bearing is roaring.

Surprising enough most cars now a days have two horns right next to each other to give a louder sound. I have also heard some people mistake their aftermarket alarm siren as an additional horn. Hope this helps.