LED w/o Resistor

Question -- I was using a pair of separately wired LED's w/ resistors. One LED stopped working, so I tried it with a replacement resistor and that didn't help. It wouldn't light w/ the resistor inline. If I hook it directly up to 12V w/o the resistor, it works fine. I can't understand why, but what are the odds of burning up my car this way? I've got it running off an A/C-D/C inverter now seeing if it'll burn up. So far so good. Any ideas?

Sublime0069 wrote:

Question -- I was using a pair of separately wired LED's w/ resistors. One LED stopped working, so I tried it with a replacement resistor and that didn't help. It wouldn't light w/ the resistor inline. If I hook it directly up to 12V w/o the resistor, it works fine. I can't understand why, but what are the odds of burning up my car this way? I've got it running off an A/C-D/C inverter now seeing if it'll burn up. So far so good. Any ideas?

As long as you have a fuse connected to it there's no chance of it burning up your car. Chances are it's on it's in the beginning stages of crapping out and you should replace it rather than push 12v into it. It's not like they cost a furtune anyway.

this might be a dumb/obvious question, but is there a resistor already connected to it? (i.e. adding the other resistor would be doubling the resistance and not allowing enough current to power it)

Yeah, don't worry, I was intelligent enough to use one resistor at a time :O)

Just went to Radioshack and bought a pack of the same type, unsoldered it from the LED, and soldered the new one on. Touch the probes, nothing. Remove resistor and touch the probes to the resistorless LED and it lights. Go figure.