Please help. I am trying to put together a low fuel warning lamp circuit using a radio shack "led" with transitors and resitors ect.
What I would like to do is use the 0-90 ohm sending unit side of the autometer fuel gauge to signal the led to light up at about 20-25 ohms or
1/8" of a tank.
I tried a circuit I found here at Team Camaro posted by SOA Nova but I could not get it to work with the "led"
I know I can buy something at Classic Industries but what fun is that
Any suggestions would be great.

Did you get it to work with the 12V radio shack light ?.

You need a window comparitor circuit. You can make one with a comparitor IC, or an op-amp and a hand full of resistors. RS should have all the parts you need. I estimate it will cost about $5 to build.