ignition activated relay to led

Printed From: the12volt.com
Forum Name: Motorcycle Electronics
Forum Discription: Installing Stereos, Alarms, Remote Starters, Lights, Garage Door Openers and other electronics on motorcycles.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=136768
Printed Date: May 02, 2025 at 12:20 PM

Topic: ignition activated relay to led

Posted By: jgby
Subject: ignition activated relay to led
Date Posted: June 08, 2014 at 12:30 PM

Hello all,

I have a Street Triple 2014 and need help with the wiring for some safety LEDs going in the plastics.

Basically I would like no power drawn while the bike is off (via relay?)
And when the bike IS on, be able to switch the lights on/off. (only using at night for better visibility.)

I would have the relay powered by the ignition somehow and have a fuse there.

Then a switch after the relay to power the lights on/off.

I'm pretty lost on which resistors and relays to use. I already have the 12V supply of course and I have a few COM-08662 UV LEDs from SparkFun I plan on using.

Any suggestions and help appreciated!

Replies:

Posted By: oldspark
Date Posted: June 08, 2014 at 5:56 PM

All you need is a switch powered by IGN +12V. There is no need for a relay.

Those LEDs are 20mA 3.0-3.6V types recommended to be run at 16-18mA (download their datasheet from SparkFun).
There are various design tools & guides on the web, or see my recent example here.
Design for the max voltage your vehicle experiences - eg, 14.4V, 14.8V.

Posted By: i am an idiot
Date Posted: June 08, 2014 at 7:01 PM

Yes, what Oldspark said.