installing fake alarm LED

[bayboy23]

i got one off ebay so it looks like i have an armed alarm so nobody steels my alpine 12's and deck and amp. i drilled the whole in the sash already but i dont know how to find a constant 12 volt source. there is a red wire that goes to 12v power source that turns on when there are no keys in the ignition, a black wire to go to a ground, and a yellow one that goes to ignition and i dont know how to wire them up. my auto shop teacher let me borrow a multimeter so that should be of some assistance. somebody please help???

 

[bayboy23]

ANYBODY??? i want this thing working!!!

 

[FROADER]

You can use the power wire for your cig lighter.

 

[Mud Bug 94]

or the red from the radio...constant.

 

[bayboy23]

what about the ignition one? and ground is just any metal ground?

 

[Phager]

Yes, the ground wire can go to any chassis ground. The yellow wire can go to anything that only recieves power when the key is in the on position, you should have two power leads going to it, one switched and one constant. If your shop teacher hasn't showed you how to do it, ask him/her how to properly back probe the wires and use the DVOM to see which wire has switched and constant power.

Hope this helps
Pat

 

[Maniak]

If you want to get fancy, you can use a relay and 3 wires..

Constant power (this will power the LED with the ignition off)
Switched power (this will power the relay when the truck is on, keeping the led off when the truck is on)
ground.

You need to hook the Constant power to the normally closed side of the relay and the output to the LED.

This way when the truck is on, the Relay has power and the normally closed side of the relay is not open. This means no power to the LED so it won't flash. When you turn off the truck the relay is no longer energized so the LED will get power from the normally closed side and will flash.

If your using a Bosch Relay (5 pin) the you would do the following.

Pin 85 is ground
Pin 86 is the switched 12V power (power is there when the truck is on)

Pin 30 is the constant 12V power
Pin 87A goes to the LED + side

The other wire on the LED goes to ground

~Mark

 

[pope_face]

A great electrical resource is the12volt.com... you have to sign up, but it's free and you can get all the information you need... you can search for the first generation Ex's and it gives you all the wiring you'd need for an alarm system, and the complete radio wiring as well...

 

[bayboy23]

i got it in, all the wiring was out and about due to my midway sound system installation and i just found the one that said ignition on it an attached the other two to the cig lighter. it turns on when the ignition is in the off position and when theres no keys in. its awesome. best $10 i ever spent. very very bright too. you can see it blinking on the front seats and roof at night so would be theives will hopefully not think twice about breaking in