replacement fuel tank sensor on/off instead of resistor

[eduardo]

my GS is highly modified and it doesn't have a fuel gauge.
It has a GSX1100 81 fuel tank

I want to set a reserve alert light.
Is there an alternative fuel sensor that works with on/off instead of the resistive mode?

tks

[Suzukian]

They are potentiometers. If you just Bend the arm so that it sits right next to the "Reserve" end of the potentiometer, the second the fuel gets to that level, the reserve light would go on. You could get rid of the gauge, and wire a light. usually it's a variable ground wire, so what you are doing is adjusting the arm to that when it floats, it hits nothing, but when it makes contact with the low end of the swiper contact surface, the connection will be made, and the light should go on. You can bench test this. It's going to be some variation of this. Remember Kirchhoff's law, you have to establish a circle to make a circuit, so there can be no "Opens'. When the swiper hits the tail end of the trace, the ground should be reestablished, and make your circuit. Just a little figuring out of the wire. I don't have one of those in my hands,b tu I have fixed enough of them on older British cars, same principle.

[slayer61]

Search the web for a float switch that suits your need. Grainger or McMaster are your friends.

[Suzukian]

slayer61 Great suggestion. I did that search, adding "gasoline' on the end to weed out sump pump type switches. I wonder how you plan to mount this thing. That will determine what you buy. I've seen a few that trigger when no more fuel is touching them, but the cost around $350 bucks. You could modify a stock fuel sending unit for much cheaper. You just have wiring that engages when the float is low, that will trigger a light. AA picture of where or how you want to mount this will make it easier to help you. modifying a stock one is the easiest, as the whole assembly could be gutted to two points touching when the float gets low, triggering you low fuel warning.

[eduardo]

I want to trigger a light on the triple clamp, which looks like this: https://cognitomoto.com/products/cus...nt=10497282369

yes, Probably modifying the original one is a good idea.

I have researched an electronic way with current comparison and I can make it work. But it's more complicated

[Suzukian]

Nicr looking triple tree clamp. U like how they have hidden the hardware (pinch bolts).