Adding extra LED to factory alarm?

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=69723
Printed Date: July 17, 2025 at 6:06 AM

Topic: Adding extra LED to factory alarm?

Posted By: Red97LT1
Subject: Adding extra LED to factory alarm?
Date Posted: January 01, 2006 at 8:29 AM

The factory alarm already has a LED on the dash and I wanted to tap into it and run another LED to the rear near my subs. The problem is,that when I try to tap into the existing wire,only one will work not both of them.Do I need a resitor or something? Thanks

Replies:

Posted By: MHARVEY
Date Posted: January 01, 2006 at 8:53 AM

this would be your best bet. but this only works if you have a flashing led

Wire the positive side of the LED to a constant (battery) 12V source. Wire the negative side of the LED to an ignition 12V source that is on only when the ignition is on.

That way your LED will only see a 12V difference across its wires when the ignition is off. When the ignition is on, both wires will have 12V and so the LED will see zero V.

Posted By: MHARVEY
Date Posted: January 01, 2006 at 8:55 AM

oh yea by the way there is a SEARCH BUTTON up at the top of the page

Posted By: Red97LT1
Date Posted: January 01, 2006 at 8:56 AM

MHARVEY wrote:

oh yea by the way there is a SEARCH BUTTON up at the top of the page

You make a post,then advise me of a search button??????????????

Posted By: MHARVEY
Date Posted: January 01, 2006 at 9:33 AM

just tryin to help out, hope thats what your looking for

Posted By: KPierson
Date Posted: January 01, 2006 at 10:05 AM

How are you hooking the 2nd LED up? In series with the OEM LED, or in parallel?

Does the OEM LED swtich the negative side, or the positive side of the LED? What kind of voltage is on the + side of the LED? What kind of car is it?

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Kevin Pierson

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