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This might not be of immediate interest to most, but it may end up being useful someday.

What: I removed the alarm siren, a quick and easy job.

Why: I have a philosophical problem with car alarms: I just don't see why they exist. They won't stop your car being stolen-- an amateur has no hope of stealing a modern car, and a professional will be totally unfazed by an alarm. They won't stop your car being broken into, since they only go off after the damage is done. At most, they are an antisocial annoyance. And the Evora's alarm is absolutely deafening when, as is generally the case, you set it off accidentally in the garage.

But more than that, there is a risk, as the unit gets older, that the internal circuitry will fail and cause it to go off randomly and unstoppably. That's because there are internal batteries in the siren unit, and when these batteries fail-- as they all must, eventually-- there's a chance that they could leak and cause a short that will set off the siren independent of anything else. Google the phrase "my car alarm won't stop going off" for some hilarious posts from around the web, and note that this is not specific to our cars. You may want to figure out how to do this on your other machines too.

How: The alarm siren is mounted to the bottom of the left-hand longeron of the front subframe. Getting to it requires removing the front undertray.

Support the car securely on some ramps or the equivalent. (I used a couple of wheel rims from a '59 Alvis and some handy lengths of 2x6. Call me old-fashioned.) The undertray comes out after removing several 8mm and 10mm bolts and two plastic crosshead screws. Note that you don't need to fully remove the bolts holding the undertray to the front bumper: you can simply loosen those and they'll slide free in the next step.

Having taken out the last of the bolts securing the undertray to the front subframe, slide the undertray forward slightly to disengage the rear from the chassis lip, and then lower and slide back.

You'll see the siren unit mounted to a small bracket, immediately to the rear of the horn unit. Note that the siren is mounted to the left-hand side of the car regardless of whether the car is LHD or RHD.

The first step in removal is to make sure that the alarm is not active. Get out from under the car for a moment, get the key and ensure that the alarm is not on. Remember that one feature of the Evora's alarm is that, when it is active, disconnecting the power will cause the siren to sound. This means that if you disconnect the siren unit while the alarm is active, that siren will go off about six inches from your ears!

Once you're sure the alarm is not active, disconnect the cable to the siren by gently prying up the clip on one side of the connector and pulling apart. It might be prudent to put some tape over the harness connector, and cable-tie it firmly to something or other, to minimize the possibility that it will get wet or short out, not that either is likely.

Two 8mm nuts secure the siren unit on either side. Loosen and remove the unit. If you forgot to turn off the alarm before, you have probably permanently damaged your hearing by this point.

And that's it! No more siren.

A note on reassembly: putting the undertray back into place probably goes easier with four hands, but it's not a bad job for one person. There are some loose spacers that have to end up on the top side of the panel, and they have been put into place by the factory with some very light adhesive, however on my car three of them came loose. Not being in my main workshop, and not having anticipated the need for some sticky stuff, I crammed a couple in as best I could and pocketed the third for the next time.

Conclusion: I was mildly concerned that the car would throw a code when the siren was removed. As you may know, the car does a system check on startup, and often will react to the absence or malfunction of an electrical item with a "wrench light" on the dashboard, which will stay lit for several seconds after the engine starts. In this case, however, it appears that the car does not care that the siren unit was removed.

So the result is a car that does not make earsplitting beeps if your door isn't quite closed when you hit the lock button, and doesn't go off like fire truck when the battery in your key fob dies and you have to open the door manually.

Good luck!

PS- Don't ask for pictures. As I said, I'm old-fashioned...
 

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I'm there with you philosophically. We should have the option of disarming any non safety related features of our cars, and most of those too. Without having to do surgery. Should be a setting. But that would never be as satisfying as just removing it or snipping some wires.

I relished the day I removed the entire alarm system and immobilizer from the Elise. Some of it probably has not yet rusted away out in the woods where it belonged.

Did you weigh it? :)
 

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Discussion Starter #3
Did you weigh it? :)
Buddy, you're hilarious. :D

I haven't weighed the siren, but I'm sorry to say it's quite light... no competitive advantage to removing it, I'm afraid.

I'm actually kind of wondering what to do with it. Generally, I like to keep the parts I pull off the Evora. (Saving them for a future concours competition, I don't know.) But because of the internal batteries, the siren's a time bomb. I feel that I ought to hack it open and snip some wires, or drown it, or something...
 

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It's ok - I'll supply the pics!

Alarm unit with one of the twin horns (there's another horn on the other side):



Undertray off:



HVAC, steering rack, etc...the alarm siren is forward of this position:

 

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Discussion Starter #5 (Edited)
Thanks for the photos! :up:

Hey, I don't mean to, er, alarm you... but I think your camera is broken. The steering rack is backwards and the pedal box is showing up on the wrong side! :D
 

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Yes thanks. Some nice stuff up in there. Like those extruded supports for the sway bar and steering rack.
 

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Great writeup guys.

A few questions I have:

1. Am I right in my understanding that there is only the one siren and that is what you take out? The whole unit since it is self battery powered like the one in the Elise was ? If it were not self battery powered you could just easily disconnect the 12 volt connector and tape it up and leave the siren in place.??

2. The photo showing the one horn is that the horns you do not touch or take out since they are the ones you honk if needed if someone were to pull out in front of you while driving?

3. Once the siren is out can you just lock and unlock the door locking mechanism with the fob just as if the siren were still in place?

Thanks for your help guys I have been wandering how to not have to worry about the car alarm going off at the wrong time and place... !
 

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Why: I have a philosophical problem with car alarms: I just don't see why they exist. They won't stop your car being stolen-- an amateur has no hope of stealing a modern car, and a professional will be totally unfazed by an alarm. They won't stop your car being broken into, since they only go off after the damage is done. At most, they are an antisocial annoyance. And the Evora's alarm is absolutely deafening when, as is generally the case, you set it off accidentally in the garage.
This made me chuckle and thought i would share a story of when I lost both key fobs (but only one key) to my Europa S. I can and do program software, so I ordered two new fobs and a key from the factory, I set about re-programming the fob, the problem was breaking in to the car set the alarm off and when I failed to program the fob again it was set off. After numerous attempts and much embarrassment at both failing to program the fob and annoy the neighbours I decided to drive the car to the local Lotus dealer......Early one morning I set off the Alarm sounds for a period of time hazards flashing then the alarm goes quite with intermittent soundings. I arrive at the garage and they too have trouble reprogramming and a new control unit has to be ordered. the factory are great as they took the two fobs I ordered back.

What I haven't highlighted is that my Wife was having a shower she heard heavy banging on the front door and persistent ringing of the door bell,so my wife wrapped in a towel and dripping opens the door to find two policemen asking if the Lotus had been stolen, so she had to explain what had happened. So I guess the alarms do work in some places :UK:
 

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Discussion Starter #12
This made me chuckle and thought i would share a story of when I lost both key fobs (but only one key) to my Europa S.

[...]

What I haven't highlighted is that my Wife was having a shower she heard heavy banging on the front door and persistent ringing of the door bell,so my wife wrapped in a towel and dripping opens the door to find two policemen asking if the Lotus had been stolen, so she had to explain what had happened.
Funny! Presumably your wife demanded to keep control of one of the new fobs so that it would never get lost again. ;)
 

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Some of the newer cars nowadays comes standard with a key-free design where you just leave the fob in your pocket. I first saw this innovation way back in 2005 with the C6 vettes. Wow can't believe it's been that long, and not more cars are using it.
 
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