fake car alarm?

Hi there

I'm new to this forum so I hope I'm doing this right....

I was wordering is it possible to "fake" a car alarm with a couple of relays and still using my orginal mountet keyless entry??

The thing I want is the car to flash once, when I lock it and twice when I unlock it? Using the turn signals

Once the car is locked,I would like to connect 2 leds that looks like a car alarm. One on the dashboard and one on the rear hatch.

The one on the rear hatch is so that I can see from my window that I've locked the car..

Any suggestions on relays or wiring diagrams??

Regards Michael

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If it jams, Force IT!! If it breaks it needed replacement anyway!!

Sorry I forgot my car is a Blazer -97 I found a wiring diagram for the keyless entry here

https://www.the12volt.com/installbay/alarmdetail/470.html

Regards Michael

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If it jams, Force IT!! If it breaks it needed replacement anyway!!

mickeymouse666 wrote:

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Sorry I forgot my car is a Blazer -97 I found a wiring diagram for the keyless entry here

https://www.the12volt.com/installbay/alarmdetail/470.html

Regards Michael

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im sure it is possible but it would be more work than its worth.



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Just find a cheap alarm on ebay.

Hello!

I’ve offered to mount a single flashing LED (with inline resistor to accommodate 12-volts) into a plastic accessory cover plate which is located in the mid-dash area of my father’s 2007 Matrix. I’ll use a fuse tap to obtain power (+) from a presently unused blade-fuse receptacle in the car’s electrical distribution center. A 1.0 amperage inline fuse will also be added for protection, and a rocker-switch will be installed underneath the dash to manually complete or interrupt the circuit as desired. A suitable ground (-) will be located somewhere behind the dash. The LED will draw a meager 30 mA of current. The total length of the circuit will probably not exceed 2-3 feet of wire.   The lead wires for the inline fuse holder, rocker-switch, and LED will most likely each have varied AWGs - some being smaller than others. Of course the power source will be 12-volts DC. This simple DIY project is intended as a deterrent to any would-be car thief.   

Although I’ve checked out this AWG table, a few people that I’ve spoken with have claimed that automotive wiring (barring wiring for stereo speakers perhaps) should never be higher than 18 gauge. However, my concern is that a heavy gauge auto wire will introduce unnecessary resistance.

How can I determine the ideal wire gauge for this basic little project? Given all these (above) factors and the low-amperage LED, does it really matter which wire gauge I select?

To the OP, it would be easier, and probably cheaper, to purchase a full car alarm and just not hook it all up if you don't want it all.  I know there are alarms that have arm and disarm triggers that can be hooked up to your actuators.  I do believe someone also makes an aftermarket alarm that is designed to work with the OEM keyless entry system.

To electrookie,

You really should have started a new thread, as your questions really have nothing to do with this topic.

30mA of current is actually a decent amount of current for a car battery.  While it's not enough to kill the battery in a day or two, it will be enough to kill it if the car sits for a 7-10 days.  I would try to reduce the current to under 10mA.

You can use wire smaller then 18awg with no issues.  The only thing you need to do is make sure you fuse it properly.  With a 1A fuse you will be fine.  There are countless OEM wires in modern cars that are smaller then 18awg.

The most important aspect of sizing wire for your application is to make sure it's not so small that it is fragile.  With a 1A fuse you can go pretty small.

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Kevin Pierson

To electrocookie, conect the ground side of the LED to ignition and the hot side to a constant live, goes out automatically when you turn on the ignition, no switch required, keep your fuse though. At 30miliamps, you can use the thinnest wire you can get away with. Note what KP said about leaving the car though, also the thicker the cable the LOWER the resistance.

Thanks guys. That pretty much answers all my questions.

Earlier I provided misinformation regarding the mention of the 2007 Matrix. Apparently this car already has a flashing LED. As I’m now told, it’s my father’s second and older vehicle where the LED is to be installed. His Matrix spawned the idea for this DIY.

The LED will probably only be activated one day each week when the car is typically parked in a somewhat troublesome area. This limited need for any sort of ‘deterrence’ would probably not justify the professional installation costs associated with an actual alarm system (remember: I'm a 'rookie'... lol). Nor would it warrant the need for an automatically switched LED in response to the ignition being turned off - either via a relay or by tapping into a switched power circuit to ground the LED’s cathode. Although these are great ideas, in this specific situation, a manually operated switch is likely preferable… as it will serve to minimize any potential battery drain problems during icy-cold Canadian winters. That having been said, as recommended by Kevin, I’ll definitely try to lower the LED’s demand for current.

This afternoon I picked up the inline ATO fuse-holder, 1 amp blade fuse, 20 gauge auto wire, and a few other odds and ends. I opted for the 20 AWG wire mainly because I felt a lighter gauge would be too awkward and flimsy to solder onto the much heavier wire of the inline components (esp. the fuse-holder leads). The actual installation won’t take place for several more weeks, when I plan to visit my parents who live in another part of the country.

As mentioned above, despite the fact that this thread has been inactive for almost 4 months, it would have been more fitting had I started a new one. If I have any additional questions related to this simple DIY project, I’ll start a new discussion thread. In any case, this will be my final post at this particular location of the forum.

Much appreciated…