led lighting on 3 volts need relay

I am making something for my car and need a relay to have the lights go on when the connection is broken or open. The led runs on 3 volts and the coil for the relay can run from 1.5 to 9 volts. I have got relays from radio shack but the SPDT does not work for some reason i run this one http://www.radioshack.com/product/index.jsp?productid=2049716&cp=2032058.2032230.2032277&allCount=24&fbn=Type%2FSPDT&f=PAD%2FProduct+Type%2FSPDT&fbc=1&parentPage=family on a 9 volt battery and it wouldn't work to turn on the light when the connection is broken. Anyone have any ideas on how to do this with a relay that would work on a 1.5-9 volt battery to light a LED? Thanks

I believe relays that are designed for 12v application need a car battery 12 volt to operate properly. A regular alkaline battery is not strong enough, let me phrase this differently, the current of the battery not the voltage matters in this application when you look at the current output capability of an auto battery vs. that of a duracell or energizer type battery. if you wire two 1.5 batteries in series and a switch it will work. I would say even a 9 volt battery will be the same, not enough current to operate the coil. This is just my opinion based on logic.The wire I'm test'n isn't doin' what it's supposed to be doin'... I am so glad I printed that tech sheet, with the wrong info.

Do it right the first time... or I might have to fix it for ya

I have two different circuits for the led and one for the coil, 9vdc bat for coil and two d cells for the led, is the coil going to overheat if its just a 9 volts directly connected.