Anyone have LED running lights in there cars? If so, how'd you get them to work?

I got mine in the mail today and went to install them.
I did the PS first, amd it lit up fine with the LED in the PS and a Filament bulb in the DS.
So I went to change the DS and when I get the LED in, both PS and DS did not work.
Checked all the fuses and they were fine, and when i put both filament bulbs in they both lit up.

Not sure why this is happeneing but Im guessing it has something to do with the small amount of power the LEDs take compared to filament bulbs.
Anyone have any input, or a solution to get these to work? Thanks.

Anyone?

Yes I think you are correct about the bulbs drawing less amperage. The autoparts store sells resistors that you attach to the wiring. It is a small rectangular prism with a wire coming out of the two ends.
It will be near the light bulb, electrical or custom interior/exterior sections

This post has been edited by Special_Edy: May 4, 2012 - 11:15 AM

Any idea what size resistor would be needed? And would they be required on both bulbs?

>
Im not sure, I think they only sell one size. Im sure the amperage draw of the incandescent bulbs isnt that much for sidemarkers, so Id say that one on one side would be sufficient. Worst case is that you blow the fuse.
Usually you need them for the blinkers. I switched to LEDs turn signals on my truck and the blinker would flash super fast or not at all till I installed them.

To find out what sort of resistor is needed, you need to know how much power the LEDs draw (in watts) and the current (amps) in the line. you'll likely need a resistor for each bulb.

do you have a multimeter? If so use it. If not, buy one. When you do go to google and look up led specifics.

Did you get the 3.5mm leds? if my memory serves me correctly from my xbox modding days, they use 3.3 V per bulb....

A little electrical engineering tells you that V=IR (voltage = current*resistance) and that voltage is ALWAYS the same when the bulbs are hooked up in PARALLEL, and voltage is reduced everytime it passes through a light or resistor etc. ... aka it drops if you hook them up in SERIES.
http://diy.sickmods.net/Tutorials/Case_Mod...D_Wiring_Guide/
That website has a nice diagram showing the difference and how 1 resistor can be used to do a string of Led's.

measure the resistances of the system with the filament bulbs in by hooking the multimeter up in parallel with respect to the filament bulbs. Replace the bulb with the LED and remeasure. The result will tell you what you need to do.

But I'm willing to bet not enough current is being eaten by the led's and something is tripping out.

Good luck

Hmm okay
I just bought 9005 bulbs with LEDs on them from ebay