Adding Idiot Light to Gas Gauge?

[colnago]

I'd like to add an idiot light to my gas gauge, like you have on modern instrument clusters, to warn me when the gas level is getting low. Has anyone done this, or know how I would wire it into the circuit without affecting my existing fuel gauge?

Thanks,

Joseph

[Kurt Combs]

I use two tanks for that purpose. I run one dry and switch to the other and then start looking for a gas station to refill the empty tank. You are going to need the expertise of a really good electronics person to answer your question.

[TNIceWolf]

I would think it would be quite a bit more complicated than simply adding a light. There would need to be some type of device to trigger the light at a certain point and hold it on until the tank was refilled above a certain level . But that is just a guess on my part so dont take too much stock in a guess and opinion.

[mrollings53]

A magnetic trigger sounds like it would work. Like the ones used on bicycle speedometers. Mount the magnet to the rod of the float, and fab up an armature to mount the sensor near the bottom of the floats travel; turning on a light when you're low on gas. The sensor would need to be gas proof though.

Or,

If such a thing exists; you could find some sort of ohm sensing device that would be attached in line to the wire from the sending unit. It would sense the ohms coming from the sender and turn on and off a light at certain measurements. It would have to not alter the ohm rating as it reads it though, so that the gauge reads correctly.