L.E.D.?

Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=31027
Printed Date: November 04, 2025 at 4:02 AM

Topic: L.E.D.?

Posted By: OHsolow
Subject: L.E.D.?
Date Posted: April 25, 2004 at 10:56 PM

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

Replies:

Posted By: CutDog504
Date Posted: April 25, 2004 at 11:51 PM

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.

Posted By: mikej9881
Date Posted: April 26, 2004 at 10:49 AM

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?

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mike

Posted By: intmd8rfn3
Date Posted: April 26, 2004 at 11:09 AM

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

Posted By: CutDog504
Date Posted: April 26, 2004 at 1:06 PM

Yeah, do what intmd8rfn3 said.

Posted By: Teken
Date Posted: April 26, 2004 at 4:42 PM

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 . . .

Posted By: OHsolow
Date Posted: April 26, 2004 at 8:51 PM

what about a switch to break the cycle?

Posted By: Teken
Date Posted: April 27, 2004 at 8:30 AM

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 . . .