Fuel gauge vs low fuel light

ginga4lyfe, Apr 12, 11:47am
Depends on the car, but most of the time it works off the guage itself, IM not sure how and i wouldnt speculate, but if you really wanted to figure out were to place the needle, its best to fill the car up to the brim and set the needle to the Full Mark, or if you can get to the sender unit easy enough you can ground the sender wire with the needle very lightly on to see which way it travels and then place it back accordingly

jono2912, Apr 12, 12:06pm
Most of the time a fuel light is turned on by a switch.

Not the conventional switch you flick on off with you hand though.

In this case, when the the switch is hot it is on, when it is cold (cooled by fuel) it is off.

This explains why fuel lights go on/off all the time.

jono2912, Apr 12, 12:07pm
Hope that makes sense.

pollymay, Apr 12, 1:03pm
They are separate unless you have something weird like and alfa then your life is over cause it probably reads it using sonar reading the tank level from the front of the car. Could work off the gauge of a coon though, who knows they are all freaking different

We had a surf where the light worked but the gauge didn't so you filled up straight away when the light came on lol

footplate1, Apr 12, 7:54pm
I understand that it is the float in the tank that activates the light.Well, in the marque have used over the last several years.

morrisman1, Oct 23, 12:53am
I can only speak for a peugeot 405 which activates the fuel light when the float drops to a certain level in the tank. There are two conductive strips that the float moves over, one is the gauge and the other is the light and it only touches the light strip once it gets low enough.