l.e.d.?

I was wondering is there any way i could fix up a led to flash when i leave the vehicle? i have various leds laying around with  pos. and neg. sides... i have a commando alarm but im really getting tired of screwing around with it....people know i have an alarm but they dont know that it is not set up..i would like to at least have the led ..just  to ward off any punk kids in the neighborhood.... by the way i would not recommend to commado alarm....any company that doesnt spend enough time to proof read their install manual for misspelled words isnt worth buying from in my opinion

All you have to do is go to Radio Shack or any other similar store and buy a 12volt flashing led. Shouldn't cost any more than 2 or 3 bucks. Then just wire up the positive to a constant +12v power source and the negative side to the ignition wire. When the car is off the ignition is grounded, therefore sending a ground to your LED, but only when the car is off.

but when you turn the car on wouldnt it  put a positive signal to both sides of the l.e.d. which would cause a short?mike

Put a diode in the ground line off the ignition. That way no positive could feed down the line.

Yeah, do what intmd8rfn3 said.

There will be voltage present regardless of the diode, there simply wont be enough current to damage the LED. Hope that clarifies the technical aspect of the diode. Regards EVIL Teken . . .

Yes you could indeed wire a switch in series to turn the LED on-off, or use a small fuse in its place. Both work well. Regards EVIL Teken . . .