how to hook up led light in car

so how do i tap into it? can u explain in detail. thanks a lot

It might be worth your while to mount the LED where you want it and run the wires to the area behind the radio, remove the radio and go to your local stereo shop and see how much they will charge you to make the connections.  Make sure to tell them that the negative wire is to be connected to the switched 12Volt wire of the radio.  If they ground the LED to ground, it will stay on all the time.

i just bought an LED light (12v) form radio shack with a built in resistor http://www.radioshack.com/product/index.jsp?productid=2062568 i hooked it up to a 3v camera battery just to test it out and it turns on but it does not blink. why is that? it says that it has a built in resistor

It is because it is not a blinking LED.  I just looked and the one I posted a link to appears to be an On-Line only item.  You may have to order it.  Years ago they stocked the item in their stores.   I do not think they carry a blinking 12 volt LED.  That is why I suggested the blinking LED and the resistor.

so i bought a blinking led but it is 5 volts. if i connect it in my car (12v) will it blow? what do i need to do to make it work? i also have a 1k ohm 1/4 watt 5% tolerance resistor

Yes if you connect the LED to your car it will blow.  But since you have the resistor, try connecting the resistor to the LED as in the picture I posted earlier, and that will prevent the LED from blowing.

i am an idiot wrote: Yes if you connect the LED to your car it will blow.  But since you have the resistor, try connecting the resistor to the LED as in the picture I posted earlier, and that will prevent the LED from blowing.

is that resistor big enough? how do i know if its the correct size in terms of watts and ohms

this is prob my last question. u have been a lot of help so far. does it matter which end of the resistor is soldered to the LED? it has bands that go from brown to gold on t.

The resistor is not direction sensitive. However there is a ground and positive connection on the LED.