newbie needs led advice/know how

Printed From: the12volt.com
Forum Name: Lights, Neon, LEDs, HIDs
Forum Discription: Under Car Lighting, Strobe Lights, Fog Lights, Headlights, HIDs, DRL, Tail Lights, Brake Lights, Dashboard Lights, WigWag, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=120582
Printed Date: May 21, 2024 at 5:50 AM

Topic: newbie needs led advice/know how

Posted By: fronzizzle
Subject: newbie needs led advice/know how
Date Posted: March 07, 2010 at 8:42 PM

I'm creating my own sub enclosure and plan on fiberglassing it. Part of the enclosure is going to include a piece of plexiglass with the word Challenger in it (I have a 2010 Challenger) and I'd like to back-light it with some red LED's. Structurally, I have the design all set but I don't know where to start with the LED.

I do not want the LED to "flash" with the music, but I do only want it to come on when the amp (radio) is on. Someone mentioned that I should be able to use the Remote On wire to get power to the LED, but I have no idea how to go about this. Plus, I've read a lot of posts about needing resistors and I have no idea if that applies to me or not. I found numerous listings of 12V LED's on ebaybut I'm not sure if that's what I need or not.

I'd really like someone to direct me on where to buy the lights (or at least what to look for) as well as some basic wiring installation instructions. Thanks.

Replies:

Posted By: i am an idiot
Date Posted: March 07, 2010 at 9:46 PM

If you use 12 volt LEDs, you will not need a resistor. The following is a diagram using the remote wire of a radio to trigger a relay to power multiple devices. Connect the LEDs and the amplifier(s) remote wires to terminal 30 of the relay.

Connecting Additional Devices to the Remote Turn On Wire (link)

Using a 30 amp SPDT relay, connect terminal #87 to constant 12 volts positive with a fuse rated to the sum of the additional accessories you've added and the components you need to turn on. (If you have two fans rated at 5 amps each and a neon light rated at 10 amps, you would use a 20 amp fuse plus 200 ma for each amplifier and processor.) Connect terminal #85 to ground, terminal #86 to the remote turn on wire from the head unit, and terminal #30 to each accessory with an appropriate fuse. A fuse (not shown) could also be used between the output of the relay (#30) and the remote turn on wire of the amplifiers and/or processors for extra precaution.
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Posted By: fronzizzle
Date Posted: March 08, 2010 at 8:43 AM

Excellent! Thank you for the information. A couple of more quick questions:

1) Where do I get the relay? Or maybe more accurate, what type (size, etc.) of relay do I need to do this?

2) I'm a little confused about the "plus 200 ma for each amplifier and processor" part. The only things I plan on running off of this are my amplifier and the LED light. What information would I need from those items to figure out what relay and fusing I would need?

Thanks again!

Posted By: t&t tech
Date Posted: March 09, 2010 at 3:48 PM

You can get the relay at any radioshack or any electronics store for that matter! The relay is a single pole double throw relay SPDT, rated at 20/30, or 30/40 should be fine! How many leds are you using? Are they twelve volt leds?

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COMMIT YOUR WAY TO JEHOVAH AND HE WILL ACT IN YOUR BEHALF. PSALMS 37:5

Posted By: fronzizzle
Date Posted: March 09, 2010 at 4:24 PM

I haven't purchased the LED's yet, but yes, they will be 12 volt. I'm not sure how many, my plan was to just buy one of the LED strips and put that where I need it. The area I'm trying to light is very small so I imagine a few lights will do.

Posted By: i am an idiot
Date Posted: March 09, 2010 at 5:28 PM

Disregard the text in my earlier post. That info was copied and pasted with the diagram. The relay will handle at least 20 amps of current. You will not but near that many LEDs on your car.

Posted By: t&t tech
Date Posted: March 09, 2010 at 8:21 PM

As mr idiot said! If you're using just one strip fuse it a five amps!

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COMMIT YOUR WAY TO JEHOVAH AND HE WILL ACT IN YOUR BEHALF. PSALMS 37:5

Posted By: fronzizzle
Date Posted: March 09, 2010 at 8:34 PM

Sorry for being dumb, but I'm a bit more confused now. Since I'm just using one strip of LEDs, that means...what? I just need the relay? That's enough to handle my amp and the LED strip?

Posted By: i am an idiot
Date Posted: March 09, 2010 at 8:53 PM

Yes the relay will be fine.