fuel level sensor to triger relay ckt

Hi,

I'm looking for a circuit which would trigger a 12V relay from a fuel level sensor so that when the fuel tank is full the relay is triggered.

I believe the fuel level sender reads 560 ohms empty and 55 ohms full. That means I would like to trigger the relay at or below 65 ohms but not higher.

This is for a '87 Vanagon and I want to disable a pump transferring fuel from my axillary tank to my main tank when my main tank is full.

Thanks for any help,

David

Hey,

I found a couple on line.

**broken link removed**

universal low fuel light, low fuel

Thanks,

D

If you are planning to leave the gauge connected to the sender, then it matters not what the resistance of the sender is; what matters is the voltage across the sender at the critical point at which you want the pump to shut off. Also, gas sloshes in the tank. It seems like you would need to have a lot of "filtering" (or hysteresis) in the voltage detector to prevent the pump from cycling on/off many times as the fuel level rises.

Good Points Mike,

I'll have to do a bit more research...

David