Circuit help?

Because the speedo and clocks were all smashed on my bike I need to make a low fuel warning light. Anyone any ideas on how I can do this? The sender in the tank I would imagine has a resistance between 50 and 300 ohms. I need some kind of circuit that would illuminate a dash LED when the resistance falls or rises?

The low fuel switch on my 81 KZ650 is fairly simple & I believe it has a 1k ohm thermistor. The original & a nos switch both tested around 1.2k ohms. It's an NTC thermistor as the resistance goes down the warmer it gets. From my notes, the one in the tank tested 4.4k ohms submerged in fuel. I plugged the nos switch into the wire harness, then turned the ignition switch to ON -->> the warning light glowed within about 30 seconds.

Battery (+) -->> ignition switch -->> Br -->> Warning light -->> G/W -->> fuel level switch/sensor --->> Bk/Y -->> Grnd (-).

Here's one I cut open.