led voltage

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=101206
Printed Date: July 19, 2025 at 3:56 PM

Topic: led voltage

Posted By: twobig86
Subject: led voltage
Date Posted: January 15, 2008 at 8:03 PM

Basically I have about 14 Blue Led's that I ripped out of my car (previous owner installed them) and I have no idea as to the voltages for them. Is there anyway to test it using my protoboard.

And if yes once I have that number how do I use it to figure out the proper resistor sizes for the leds?

Replies:

Posted By: tedmond
Date Posted: January 16, 2008 at 2:59 PM

were all 14 wired together? or spererated?

Posted By: twobig86
Date Posted: January 17, 2008 at 11:27 AM

he had them wired in groups of say 2 or 4 or 5 it was all randomly done thats why I disconnected them. I am now looking to regroup them but I dont know anything about them except that they are blue leds...so basically are they useless now or what?

Posted By: tedmond
Date Posted: January 17, 2008 at 2:46 PM

they are not useless, they are still functional. if you plan to wire them seperatly a 480 - 550 ohm resistor will do for each bulb. or you can wire them in series in multiples. may i ask where you might be placing them?

Posted By: twobig86
Date Posted: January 21, 2008 at 4:41 PM

I was going to wire them under the dash to get a blue glow by my feet and the passenger's feet. I was thinking of wiring them in groups of say 4 or 3 so if I was to do that how does the math work. is it say 480 ohm / 3 then one of those for each one? Also I dont have them infront of me but I have about 14 so if you could just do a simple example of how the math works so i can wire it all properly.

Also if im doing groups of 4 would parallel not be better incase one blows? Or is series recommended?

Posted By: tedmond
Date Posted: January 22, 2008 at 7:37 PM

well LEDs have the long life span, but it might be as bright as underglow(neon) doing a google search on LED calculator will bring up many pages. Using one of the online guides will work for you.