2000 LS400 alarm siren location. Help needed.

[DanMystro]

Does anyone know where the alarm siren location is for a 2000 LS400, my alarm keeps going off randomly, I've read the radar under the centre console can trigger if metallic objects are in the arm rest, I've removed literally everything and it still goes off, I even turned down the knob 'minus' as far as it goes and even removed it and it still went off by itself.
 

So my next step is to just disconnect the sirens, any help much appreciated.

[Razor61]

I think it's in the drivers front wing/inner arch area, at the front behind the bumper iirc.
You will need to remove front of the wheel arch liner to get to it I presume.

[cruisermark]

Hi

How old is your Battery? - Have you checked to see its not failing as a low Battery can cause this?

 

[Razor61]

Maybe not at the 

3 minutes ago, Razor61 said:

I think it's in the drivers front wing/inner arch area, at the front behind the bumper iirc.
You will need to remove front of the wheel arch liner to get to it I presume.

Maybe not exactly where I said in the inner wing area looking at the manual.

[DanMystro]

2 minutes ago, cruisermark said:

Hi

How old is your battery? - Have you checked to see its not failing as a low battery can cause this?

 

Hi cruisermark, thanks for the reply. My Battery is only a few months old so it shouldn't be that. I can play music, have the lights on etc. and the power draw is fine.

[DanMystro]

Just now, Razor61 said:

Maybe not at the 

Maybe not exactly where I said in the inner wing area looking at the manual.

Hi Razor61, thank you for this! Will definitely have a look now!

[steve2006]

It is located in the driver’s side wheel arch but up left towards where the A pillar comes down, basically under the bonnet hinge. 

[DanMystro]

41 minutes ago, steve2006 said:

It is located in the driver’s side wheel arch but up left towards where the A pillar comes down, basically under the bonnet hinge. 

Thank you Steve. I've found a horn near that location but under the bonnet, is this the same thing? 

 

Edit: Also just found this that literally says 'Buzzer' 

 

Edit: Don't worry, think I found it. Third picture. 

[DanMystro]

Thank you for all the help, people. I located the siren and have since disconnected it, it was in the wheel arch behind the offside indicator. Activated the alarm on purpose and disconnected the siren to make sure that was it, job done.

[Cotswold Pete]

18 hours ago, DanMystro said:

Thank you for all the help, people. I located the siren and have since disconnected it, it was in the wheel arch behind the offside indicator. Activated the alarm on purpose and disconnected the siren to make sure that was it, job done.

Nice one,  I assume your lights just flash and silence prevails.

My random alarm is really random, sometimes a long motorway drive is the trigger for it to go off 20 seconds after locking, sometimes it seem the be using the moonroof, and I wonder if when I close the roof, some sensor is not quite engaged (but that seems like a silly suggestion).

I might have a look at doing the same thing, as notice as the car gets older the alarm does seem more random

[DanMystro]

1 hour ago, Cotswold Pete said:

Nice one,  I assume your lights just flash and silence prevails.

My random alarm is really random, sometimes a long motorway drive is the trigger for it to go off 20 seconds after locking, sometimes it seem the be using the moonroof, and I wonder if when I close the roof, some sensor is not quite engaged (but that seems like a silly suggestion).

I might have a look at doing the same thing, as notice as the car gets older the alarm does seem more random

Hi Cotswold Pete, so when the alarm would go off because I think it was for illegitimate reasons i.e faulty, only the siren would go off, no horn and no flashing lights. The only way to stop it was to disconnect the Battery.

Since removing just the siren I've purposeful activated the alarm to test it and the horn blares & lights flash, so at least those work in case of a legitimate reason for the alarm to go off.

[Cotswold Pete]

1 hour ago, DanMystro said:

Hi Cotswold Pete, so when the alarm would go off because I think it was for illegitimate reasons i.e faulty, only the siren would go off, no horn and no flashing lights. The only way to stop it was to disconnect the battery.

Since removing just the siren I've purposeful activated the alarm to test it and the horn blares & lights flash, so at least those work in case of a legitimate reason for the alarm to go off.

Dan,

I see what you mean, I maybe need to observe exactly what happens when mine goes illegitimate alarm

[DanMystro]

2 minutes ago, Cotswold Pete said:

Dan,

I see what you mean, I maybe need to observe exactly what happens when mine goes illegitimate alarm

I wish you the best of luck on sorting your alarm problems!

[Malc]

let's remember these cars of ours are now very aged and electronics and electrics have a habit of weirdly degrading with no clear but random effects with such age

Good luck finding the solutions

Malc

[DanMystro]

3 hours ago, Malc said:

let's remember these cars of ours are now very aged and electronics and electrics have a habit of weirdly degrading with no clear but random effects with such age

Good luck finding the solutions

Malc

Hi Malc, thank you for the comment. I remedied the problem by just disconnecting the siren. All is good!

[LenT]

17 minutes ago, DanMystro said:

Hi Malc, thank you for the comment. I remedied the problem by just disconnecting the siren. All is good!

If I’ve understood you correctly, Dan, this means that the alarm will no longer sound even if there’s a legitimate cause for it to do so.  So you’ve stopped the symptom but not solved the problem?

Do you propose to regard this as a temporary respite while you continue to investigate the cause, troublesome though it clearly is?

 

[Malc]

16 minutes ago, LenT said:

Do you propose to regard this as a temporary respite while you continue to investigate the cause, troublesome though it clearly is?

Personally on my Ls400 a while back i was fortunate to relieve the blo--ody sound of the alarm going off willy nilly by just turning down the dial under the console area

Malc

[LenT]

2 hours ago, Malc said:

Personally on my Ls400 a while back i was fortunate to relieve the blo--ody sound of the alarm going off willy nilly by just turning down the dial under the console area.

I don’t seem to have such a button.  But what I do have is a button on the roof near the interior mirror, as part of the moonroof/ front interior lights unit, that sets the intrusion and tilt sensor.

If you set this to Off it disables the alarm system.  If it’s On I wonder if it accounts for the erratic behaviour that Dan’s experiencing?

[DanMystro]

2 hours ago, LenT said:

If I’ve understood you correctly, Dan, this means that the alarm will no longer sound even if there’s a legitimate cause for it to do so.  So you’ve stopped the symptom but not solved the problem?

Do you propose to regard this as a temporary respite while you continue to investigate the cause, troublesome though it clearly is?

 

No, because the horns still blare and lights still flash in-case of a legitimate cause, I tested this by following the manual on how to 'activate the alarm', the only thing that was going off by itself was the siren.

For the time being I'll leave it as is, I can live with the alarm just being the horn and lights, the siren was the main problem, it would just go off by itself with no accompanying horn or flashing lights.

I don't suppose you have a picture of said button near the interior mirror? I've had a look and could only find buttons for the moonroof and dome lights.

[DanMystro]

2 hours ago, Malc said:

Personally on my Ls400 a while back i was fortunate to relieve the blo--ody sound of the alarm going off willy nilly by just turning down the dial under the console area

Malc

Yeah, I went to do that but found out it was already turned all the way down, I even took the radar box out to have a gander and the siren went off whilst I was inside.

[LenT]

4 hours ago, DanMystro said:

 

 

[LenT]

4 hours ago, DanMystro said:

I don't suppose you have a picture of said button near the interior mirror? I've had a look and could only find buttons for the moonroof and dome lights.

I hope this will do, Dan.  But by the sound of it, if you have said button, it may be elsewhere.  Its function Is described in my Manual in a section headed ‘anti-theft deterrent’.

But while I have the button, I don’t have the siren.  Or at least, not one that I have yet discovered.

 

[DanMystro]

18 minutes ago, LenT said:

I hope this will do, Dan.  But by the sound of it, if you have said button, it may be elsewhere.  Its function Is described in my Manual in a section headed ‘anti-theft deterrent’.

But while I have the button, I don’t have the siren.  Or at least, not one that I have yet discovered.

 

Oh, your panel looks entirely different to mine, what car is this from?

Thanks.

[LenT]

10 minutes ago, DanMystro said:

Oh, your panel looks entirely different to mine, what car is this from?

Thanks.

2015 IS 250 Premier.  In fact, it was only because I thought it might be of some help that I looked up its function.

So at least I’ve learnt something!  

[BigBoomer]

The same button is on the sunglasses holder on my LS430, but I am pretty certain that it does not exist on the LS400.
The Siren has it's own internal Battery and can be triggered by someone disconnecting the main car Battery, so it may be that your Battery is low and that is triggering just the Siren.
If something triggers the main car alarm, then it should also trigger the Siren.
If I were you I'd check that my Battery was in good nick and holding a decent charge (need a load tester) and if that was all good, I'd start looking at the wiring between the Siren and the Battery as there may be a bad connection or intermittent wire there somewhere.