led stays on dim when switch is off
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=123657
Printed Date: July 12, 2025 at 8:24 PM
Topic: led stays on dim when switch is off
Posted By: gill41083
Subject: led stays on dim when switch is off
Date Posted: September 24, 2010 at 1:48 PM
im putting leds in all the interior lights on a 94 pathfinder, but i cant get them to turn all the way off, there is .7 of a volt when the switch is off, i tried using a resistor but coud not get it to turn off with that either, any one got any ideas?
Replies:
Posted By: oldspark
Date Posted: September 24, 2010 at 6:42 PM
Add a series diode or 2 to drop the 0.7V.
Posted By: awdeclipse
Date Posted: September 27, 2010 at 9:40 AM
How did you wire the resistor you tried to add? In series with the LED or did you wire it to GND? Similar to a pull-down resistor.
Posted By: gill41083
Date Posted: September 27, 2010 at 3:22 PM
i wired it just about every way possible lol, what size diode should i use to get rid of the left over voltage?
Posted By: oldspark
Date Posted: September 27, 2010 at 7:06 PM
Almost anything. If just a single LED (string), signal diodes like 1N914 or 1N414 etc.
Or common power diodes like 1N400x (1N4004 etc).
Just not low-voltage Schottky or germanium.
As long as its 0.5V or more it should be ok (otherwise use 2 in series), but a diode should not light on 0.2v etc.
Are you sure you don;t have bleed-thru current on whatever is powering it? Even 1mA is enough to light a LED significantly (but I didn't think 0.7V was).
|