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Fake Alarm LED Wiring

Posted: Sun Jul 04, 2010 1:09 am
by milobob
Hi guys,

Been wanting to install a flashing red LED to where the alarm light is suppose to be. I know some of you may think this is silly but personally its something I can do with my free time and is somewhat of a petty theft deterrent.

My question was, if I was to get a blinking LED from ebay/whereever, which wires would I splice into?

Found some simple wiring instructions:
1, Connect BLACK wire to chassis ground

2, Connect RED wire to fuse block that has 12 volts when vehicle is running or not (Hot at all times)

3, Connect YELLOW wire to fuse block that has 12 volts only when vehicle is running (Hot when running)

OR

red wire to +12V power and the black wire to +12V Acc or ignition


Also, just another question off topic - is it ok to run one low beam @ 51w and one at 55w?

Posted: Sun Jul 04, 2010 6:06 am
by AJjnr86
Yea, u won't do any damage, it just means the 55w will b marginally brighter, but I don't think u would b able to tell the diff

Re: Fake Alarm LED Wiring

Posted: Sun Jul 04, 2010 12:58 pm
by Blakey
milobob wrote:Hi guys,

Been wanting to install a flashing red LED to where the alarm light is suppose to be. I know some of you may think this is silly but personally its something I can do with my free time and is somewhat of a petty theft deterrent.

My question was, if I was to get a blinking LED from ebay/whereever, which wires would I splice into?

Found some simple wiring instructions:
1, Connect BLACK wire to chassis ground

2, Connect RED wire to fuse block that has 12 volts when vehicle is running or not (Hot at all times)

3, Connect YELLOW wire to fuse block that has 12 volts only when vehicle is running (Hot when running)

OR

red wire to +12V power and the black wire to +12V Acc or ignition


Also, just another question off topic - is it ok to run one low beam @ 51w and one at 55w?


im confused at how you are getting to run one headlight at 51W unless you have bought a 51W headlight. the headlight wattage wont change unless you undervolt it.

Posted: Sun Jul 04, 2010 1:45 pm
by milobob
I bought a pair of headlights - one was 51w and one was 55w...

Posted: Sun Jul 04, 2010 2:17 pm
by Graham
You could connect it to a permenant positive source and have some sort of module set up to blink every x amount of seconds.

You could get a cheap LED from eBay or I'd suggest getting a prewired 5mm LED & a metal LED holder from oznium.

Wiring it up would be easy enough but I'm not sure how to get it to flash when the car is off, some sort of tricky stuff would be involved

Posted: Sun Jul 04, 2010 4:16 pm
by Blakey
...

Posted: Sun Jul 04, 2010 10:43 pm
by draevon
I had one of these in my old car and will do one in this car eventually. Run a NC relay from constant 12v with the ACC/cigarette lighter as the switching circuit. Buy a cheap flashing LED and hide it wired in series with a nicer looking constant Blue/red with a chrome housing. Flashes when car is off, stops flashing when car is on. Job done.

Posted: Mon Jul 05, 2010 12:26 am
by milobob
Na, I'm planning it stuff it into where the alarm LED is suppose to be...

Just need to figure out where to put the negative terminal lol!

Posted: Mon Jul 05, 2010 7:09 am
by Blakey
milobob wrote:Na, I'm planning it stuff it into where the alarm LED is suppose to be...

Just need to figure out where to put the negative terminal lol!


where is it ment to be?

Posted: Mon Jul 05, 2010 9:49 am
by smithsy
From a electrical point of view I can't see any reason why you'd need balanced loads for your headlights because when one blows your essintially using 0W on one side and then the full 51/55W on the other and it causesno problems...

On the note of the false alarm wiring, it's something I had thought about for a while, but in the end I just put a real alarm in.

Two options would be to work out how to hook upto the LED that's located next to the hazard light button. There are two wires in the loom going to it you can tap into the LED circuit which consists of a SMD resistor in line with a SMD red LED. From my brief look at it, it seems to need upto a 12V voltage hooked upto it. So if you could work out some sort of electronic circuit that pulses 12V and consumes low power then that's one option.

The second option is to hook up a relay onto the accessories power in the car (ie. at the back of the stereo for a nice easy to locate power source), then run off the NC (normally closed) contact a premade flashing LED that you can get from Jaycar or a capacitor based LED flasher circuit which run from a constant 12V supply (which can also be found at the loom for the stereo)

Posted: Mon Jul 05, 2010 10:39 am
by Graham
Blakey wrote:pre wired stuff is there just to let guys sell 5c LED's for $4


And to save people the time and effort who don't know how to solder/wire LED's.

Posted: Mon Jul 05, 2010 12:16 pm
by Blakey
...

Posted: Mon Jul 05, 2010 12:29 pm
by dannyboi
I brought the issue up regarding the flashing indicator in one of the Alarm threads.

Seems a bit annoying to have a redundant indicator area, when cars like the Camrys have a light to indicate whether a correct key has been inserted or not.

Posted: Mon Jul 05, 2010 6:36 pm
by Graham
Blakey wrote:Yer but $4 for100 led's plus 2 sec soldering and 30c for 100resistors. From my point of view the saveings in time just don't, equate to how. Much pre wired led's are. The saying more bang for your buck. Just doesn't work for prewired leds lol cause your not even getting 1/36 of what they really should cost.


Of course everything will be cheaper when you buy the parts and do it yourself, but you can't expect people with little to no experience to solder LED's and resistors together and wrap them in heatshrink tube and add wire to it..

I guess you could look at it the same way with fast food.

$5.25 for a simple burger from KFC

2 pieces of bread
a few grams of lettuce
a cooked piece of chicken
a small amount of mayo.


$5 for 6 burger buns
$2 for a head lettuce
$15 for 6 fillets of chicken (?)
$4 for a bottle of mayo

6 burgers would cost $31.50 from kfc
the ingredients you could buy to make it yourself would cost $26 which is less.

Not having a go or anything but sometimes it's easier to pay for stuff that's already made or prewired, even if the markup price is thousands of % from what it would cost to make originally.

Posted: Mon Jul 05, 2010 6:38 pm
by smithsy
Blakey wrote:Yer but $4 for100 led's plus 2 sec soldering and 30c for 100resistors. From my point of view the saveings in time just don't, equate to how. Much pre wired led's are. The saying more bang for your buck. Just doesn't work for prewired leds lol cause your not even getting 1/36 of what they really should cost.


But if they only want ONE (ie not 100) then it's cheaper (even moreso given they'd also have to buy heatshrink) and quicker for them to just buy the $4 pre-made one.

EDIT: Ooops looked like Graham pipped me to the post :lol: