led lighting in a spare pocket

So I have this little project I'm doing. I drilled two small holes in my spare pocket and placed in 2 5mm Blue LEDs. What I want to do is have them light up when I turn on my dash lights. Since I'm not using my illumination wire on my aftermarket harness I was wondering if I can use this to power my LEDs (assuming ill. is what lights the dash). Or would it be the dimmer supply? I would like it so that when I control the brightness on the dash my LEDs will also dim and brighten. I would then ground it through my radio? Or would grounding through the radio cause a poor ground? Also the LEDs are rated at a min. Vf of 2.8, typical Vf 3.0 and a max. Vf of 3.3. Should I just go by the Typical Vf of 3.0? Forward current is 30mA. So my math turns out: 12.4v - 2 LEDs @ 3.0Vf typical / .03 = 213.3333. Now is a 220ohms resistor okay to use? Should I use 210ohms? or should I take into account the min. and max. voltages and go by those voltages? Thanks guys/gals!"God invented man, and man invented the metric system."

- Salvador Dali

you should be able to use your illumination wire.  u can easily find it hooked on your stock radio, or in that harness that your radio uses (most cars anyway)  you can check it with a volt meter to make sure it does what you want.   i cant think of any other easy access wire.   Your LED's draw litteraly nothing, so you dont need to worrie about proper grounds and stuff.  just touch it to anything metal thats not painted, and it will work..   Your leds are a strange voltage, normally they all are .2 volts more..   i guess it doesnt matter.   what you should do is buy each LED its own resistor.  when you do the math you get12.4 volts - 3. volts  / .03 =   313 Ohms.   now, its a strage resistor size, so i would go with one that is HIGHER.   its not good practice to rate them for the right resistor.   your Voltage can easily go up while driving, so its important your LED can handle the voltage change.   now, normally i say by defualt to use a 470 ohm resistor for most LEDs that are 3.2 volts, but u can use a smaller one.    i would still reccumend the 470 resistor, but maybe a 330 or higher will work fine.   dont ever rate an LED by its max.  anything over the max will blow the LED, or decreese it brightness to almost nothing.   always use the least amount of voltage you can, and stay away from the max.i wouldnt double up the LED's so they use 1 resistor unless u really want to.  resistors only cost about $.01 each, but normally when sold is smaller quanitys can be $.05 - $.50 each.. so dont get fooled if u see one for like $1.00  .. let me know if i forgot anything, or u wanna ask anything else.. i try to stay updated with the forums, but i forget to check them offten like i should.    

I am pretty positive the voltage at my battery is 12.4v. I have to double check on the exact voltage. Now if I did go with a resistor per LED to get a 313 Ohm rating how much higher should I go? 320? 350? More? Or should I just use the 470 Ohm resistor regardless? Also why wouldn't you double up on LEDs? I would wire them in series so I didn't think it'd be a problem? I'm not worried about buying resistors. I can probably get a few free but even if I have to spend $2.00 I could care less. I'm not worried price wise lol. I was thinking if I should put in 2 more LEDs to bring the voltage up to 12 and perhaps not worry about the resistors. Does this really matter though? Meaning is one method better than the other, or is it just two different ways of getting to the same point (for the most part the same)? I think that's everything else. If any of you would like pictures I'd be glad to post (I might anyway if I can). I know this really isn't the most complicated project for most but I am still new to this stuff, so I appreciate any and all input and patience."God invented man, and man invented the metric system."

- Salvador Dali

Sorry to double post but here's the specs on the LEDs I'm using. "God invented man, and man invented the metric system."

- Salvador Dali

So the voltage at my battery is 13.05 when the car is off and 13.95 when the car is running. The only thing about wiring up the LEDs in series is that I feel the end result will look a lot neater. But on to the math (since I am horrible at it). I could do either of the following. 14v - 3 / .03 = 366.6667 14v - 6 / .03 = 266.6667 Should I just use 470 Ohm resistor overall? Or should I cater to each one? i.e. a 470 in parallel and a 330 (if that's a size) in series? I just want to know which wiring option I can do would be best. Any other suggestions would be appreciated. Anything worth doing is worth doing right (assuming I am able to do it, lol), correct? :P"God invented man, and man invented the metric system."

- Salvador Dali

Thanks a lot guys, helped me out a lot. I still don't know how it will all be wired, but I will figure that part out when I'm ready to put it all together and pick up the resistors. I'm only really debating this because I started some of the wiring last week and I had set it up already for series wiring. Nothing permanent but all I really had to do now was solder and hook up the wires to power. Oh well though!"God invented man, and man invented the metric system."

- Salvador Dali