Wiring help! Question more like it.

[ToolGuy]

Was wondering if someone knew of a wire that is live when the key is off or out of the ignition and NOT live when the key is on or engine running?I want to install a flashing LED light as a security system LED and my car does not have the factory installed Security LED. Thanks,

[joatmon]

I don't know of one. I remember looking for one for some other project.You could use a relay that would activate when the car was on, and using a relay that had normally closed contacts, ot would open when activates, so when you turned the car off, the relay would close the contacts and send power to the LED. But I don't think there is a handy thing to just plug in to. or just put a switch somewhere, go for manual controlDo you have a flashing LED thing already, just need to find 12V and ground that are there only when you want, or are you also looking for a way to flash the LED?

[ToolGuy]

The relay idea just may work! And yep, I have a red flashing LED just need the switched power source.

[vibe-04]

The interior dome light is switched at the dash and "I think" would have a hot lead to it. Actually, re-reading your post this wouldn't work unless you put a switch on your dash as well. Still simple but a relay would be cleaner.

[Baltovibe]

I installed a blinking LED; just tapped off the dimmer control switch. Of course, it does blink all the time, but because it is located in the left switch panel, it is not noticable while driving.http://forums.genvibe.com/zerothread?id=22925

[joatmon]

You would want a relay with normally closed contacts, something that when there was no vltage on the relay coil, the switched contacts were connected, and when the relay activates, it opens the switched contacts.You could hook one side of the relay coil to 12V, and the gound side of the relay coil up to the output of the key sensor switch. This switch is an open circuit when the key is out, but connects to a ground when the key is in. Put the key in, the relay activates, and disconneccts power to the flashing LED. Take the key out, the relay goes back to normal, closing it's contacts, and turning on the LED. The wiring diagrams I have show that the key switch wire is "L-B", which should mean blue with a black stripe. It should run from the ignition switch to either pin 15 on the 2003 instrument cluster, or to pin 12 of the factory alarm module. If you had the factory alarm you wouldn't be needing/wanting to do this in the first place, but it is possible that the wire is run to both connectors just in case, but I can't say. If I were doing it, I'd probably use a tiny 12v relay from RadioShack, maybe even this oneThat is just one potential alternative.