Add on alarm LED opinions
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=67379
Printed Date: July 21, 2025 at 10:07 PM
Topic: Add on alarm LED opinions
Posted By: 808vip
Subject: Add on alarm LED opinions
Date Posted: December 01, 2005 at 1:51 AM
I've been searching the web looking for LEDs to replace the ones I currently have installed in the doors. I've been using this certain brand of LEDs but every time I have to disconnect them they seem to burn out when I reconnect them. Is this common with all LEDs? (this next question may be obvious) Do I need to disconnect the battery every time I have to disconnect them?
Is there a favorite brand of LEDs out there that installers prefer over the other?
Replies:
Posted By: redpeppers
Date Posted: December 01, 2005 at 2:00 AM
i use dei brand leds...
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Where theres is a wire there's a way.
Posted By: KPierson
Date Posted: December 01, 2005 at 7:44 AM
I buy all my LEDs off of Ebay, super cheap and the only times I damage them is when I heat them too long with a heat gun (heat shrinking the pins). I connected and disconnect them frequently without any issues.
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Kevin Pierson
Posted By: dualsport
Date Posted: December 01, 2005 at 11:06 AM
What are you using to drive the LEDs with?
If it really burns out every time you reconnect them, but are fine otherwise, only thing I can think of may be that your circuit has some capacitance on the output that results in a large current surge being applied to the LED and blowing it out. When it's in circuit, the normal resistance limits the current.
Just speculation, you have to see how you've got it connected-
Posted By: tragik
Date Posted: December 01, 2005 at 11:13 PM
I am with dual sport on this. Electrically there is no difference between reconnecting an LED and just turning it on. The LED brand isn't important. Most manufacturers (Varad, DEI, streetglow, etc.) don't manufacture their own LED's anyhow, they buy the overseas and use them for specific aplications with thier brand name. Keep in mind that alot of LEDs operate at 3 volts, and 12 volts will pop them. If you are using raw LED's(that is, ones that aren't speifically made for 12 aplications, you need to have a 1k resistor in line with the thier power source.
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Northstart.....or start it your damn self.
Posted By: dualsport
Date Posted: December 02, 2005 at 8:56 AM
Yeah, I assume the limiting resistor is in place if it works for a long time while it's hooked up, and only blows if it gets reconnected.
If it were hooked up in some funky way like this, it could blow on reconnection, since the cap would charge up to the full 12V and blast the LED with a big current surge, assuming the cap were large enough.
Other thing might be electrostatic discharge, but LED's aren't particularly sensitive to that, so I doubt that would be it.
Posted By: 808vip
Date Posted: December 02, 2005 at 10:55 AM
I posted this earlier but i don't see it:
I have a Clifford Matrix 751 with two Varad leds , one in each door. I believe their hooked in parallel ( + to + to + and - to- to- ?)
Posted By: dualsport
Date Posted: December 02, 2005 at 11:16 AM
Haven't had any experience with the Varad leds, but from prior posts on them, it seems that it's a module with three wires, two for power and one for controlling the turn on/off of the LEDs when grounded. Is that what you're working with? Don't know what they're using for the switching, but if it's a MOSFET or something, it could be sensitive to ESD; maybe the gate's getting damaged when you have it open. Seems unlikely that a commercial product wouldn't be protected against that though. You might just want to take precautions against building a static charge when you handle it by touching a ground before you handle it; always a good idea for anything electronic.
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