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waddep. I reposted this in gen discussion since other gens may need this too. If some local neighborhood moderators could delete my old one? I have a 96 CX without an empty light and I would like to add an empty light since mine didn't come with one. I know once the needle drops below the empty line that I am in the poo poo land but sometimes I have others drive my car (most of the times when I'm sh!tfaced wasted ) and I have had them run out of fuel as well. Point is, I want to add one.


At empty le resistance is 105-110ohm at empty and 2-5ohm at full. I recognize that I need to hook up a circuit so that a light comes on when le resistance is 105-110 ohm. Here is where I need help from you electrical nerds since its been 7 years since my last electronics class.

How would I go about doing this as this is counter intuitive to the on/off toggle electronics that I normally install

 
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Using a voltage comparator or a Zener diode would be the best. Find out what the voltage is when the resistance is 95 or 100 ohms. There are different types of Zeners that conduct at different voltages so you should be able to find one that conducts at the voltage you need. A voltage comparator is a simple circuit you can build if that is better for you.

 
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So should I quick splice the signal wire at the pump and run an LED to where the empty light is on the dash?

 
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Yes. Either at the pum

 
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Yes at the pump or at a connector closer to the dash. Splice into it at the signal wire then go to your voltage comparator circuit, or Zener, then positive side of LED. You may need a resistor to step down the voltage for the resistor depending on the voltage rating of the LED. Then ground the LED.