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im wanting to add a low fuel level light to my car. it has a fuel gauge, 33 ohms full 270 ohms empty. the tank has two terminals, one to the body for ground and one directly into the back of the gauge. I've been doing a bit of research and understand how a lm3914 works and have a DIY kit coming with the leds to learn more and I'm confident I can make this work. the issue I can figure out is how to convert the ohms to volts as the lm3914 reads the volts to light up various stages of leds this may just be a case of trial and error?

smyffe96
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    Do you want to simply have this sensor operate with the LM3914 alone, or does the car also have an existing fuel display that you want to keep? – Neil_UK Dec 10 '22 at 09:33
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    start by measuring the voltage on the wire that connects the tank to the gauge – jsotola Dec 10 '22 at 17:20
  • @Neil_UK I have a speedhut fuel gauge (after market) which has a single wire that goes back to the fuel level sender. I want to keep this. I had assumed I could simply run two wires off the single terminal – smyffe96 Dec 11 '22 at 06:36
  • @jsotola ok I will try that. I had assumed that the current gauge would be reading the ohms not volts? is this naive? everything always ohms volts and amps? – smyffe96 Dec 11 '22 at 06:40
  • never assume anything ... always measure – jsotola Dec 11 '22 at 07:10

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