DIY Car alarm?

Loads of car break ins on my block last night. It happens a lot, but we're typically spared. Well, last night they broke into the 4Runner. Took the $6.00 in change and the ash tray. No big deal, but broke the damn window. Now I have to get that fixed.

Anyhow, I got to thinking. First off, my neighbor has the right idea. Leave the car unlocked with nothing in it. I think we're going to do that. But I'm thinking about something that will chase them off. I don't think it would take a lot to chase off a petty crook like this. Obviously looking for a few bucks in change. They have to be scared, so I'm thinking just about anything would get them to be on their way.

So I was looking at a super loud piezo alarm to mount inside the car. Maybe a couple of them. Loud enough to make it painful to enter the car. But I want to keep it cheap and simple. Okay, if the car isn't locked then they open the door. My neighbor's door was opened last night, but no broken glass. So at least this time, it seems they do check.

I figure I can wire something to the dome light circuit. Put a switch somewhere outside the car - like in the front fender lining. Easy to get to but not obvious. Interior LED to confirm it's on or off before you open the door. Then use a relay to power the sirens. But it would be nice to figure out a way to get them to stay on for like a minute, even if the door is closed again. Is there an inexpensive and simple way to do that?

If I can make it cheap and simple enough I may just build five or six of them and offer them to the neighbors too. I'm guessing they leave once the run into something like that, so if I can get them before the even get to my cars, all the better.

Any thoughts?

Here's the alarm I'm looking at.

http://www.ebay.com/itm/Anti-Theft-High-dB-Lond-Mini-Piezo-Siren-Car-alarm-/260741341457?pt=LH_DefaultDomain_0&vxp=mtr&hash=item3cb5652111

Good point- didn't think to check that. It's a '98. Don't know if they started that yet, but my '91 MR2 does.

why diy a loud piezo when a basic "real" alarm is like $30 and has the cool remote to disable it when you get in the car.

example: http://thebettersource.com/index.php?dispatch=products.view&product_id=668

I'd like to use one of super loud industrial alarms. You know, like the ones in the movies when the power plant is about to melt down? Mount that under the seat with a blinding bright light somewhere in the car. Did I mention the doors should be locking the thief in about now?

My son, who is in the alarm business, put one in his 300zx that would deafen you. Both high frequency and low, inside sirens. Absolutely painful. This was not an off-the-shelf creation, and cost him a few dollars to build. Never had an attempt afterward, so don't really know how effective it would be. Probably very.

Fill a glass container with 10k Africanized bees. Rig a 5lb hammer to smash it when the door is opened.

Mean dogs (Rottweiller, Doberman, Bull Mastiff, etc) leased to outside of vehicle. No more problems, other than feeding them.

I vote this.

http://www.youtube.com/watch?v=pRB6XXuWQm8

81cpcamaro wrote: Mean dogs (Rottweiller, Doberman, Bull Mastiff, etc) locked inside vehicle. No more problems, other than feeding them. And the smell.

Fixed that for you.

whoever put the alarm in my impala put the speaker under the dash - god forbid you hit the arm or disarm button when you're in the car...

None of it stops them from smashing out your window.

Leaving the doors unlocked may cause them to actually try the handle first, but a whole lot just smash the glass before checking.

foxtrapper wrote: None of it stops them from smashing out your window. Leaving the doors unlocked may cause them to actually try the handle first, but a whole lot just smash the glass before checking.

So, do you have any suggestions?

A worthless target gets far less attention than a tasty one.

Don't leave valuables in the vehicle, don't make it look like the vehicle ever has held valuables. Don't put out bait that will attract a thief.

Accept that there is nothing you can do for the true vandal who is determined to smash windows and kick in doors or slash tires.

81cpcamaro wrote: Mean dogs (Rottweiller, Doberman, Bull Mastiff, etc) leased to outside of vehicle. No more problems, other than feeding them.

I vote a tiger in the car.

I've always been partial to this.

http://www.youtube.com/watch?v=OmpBYcM06Sk

93EXCivic wrote:

81cpcamaro wrote: Mean dogs (Rottweiller, Doberman, Bull Mastiff, etc) leased to outside of vehicle. No more problems, other than feeding them.

I vote a tiger in the car.

Great idea, harder to get a tiger though. Maybe a rescue panther instead? (bad commercial reference, sorry).

foxtrapper wrote: A worthless target gets far less attention than a tasty one. Don't leave valuables in the vehicle, don't make it look like the vehicle ever has held valuables. Don't put out bait that will attract a thief.

It's a 1998 4Runner. Hardkly a tasty target. They smashed the window and took the ash tray. Could have been empty for all they knew. As it is, it had a few bucks in change. That's all they got. I got to buy a new window.