question about fuel sending unit

[Tamatalon39]

Ok so I just got my Talon running pretty good and i have an issue where my fuel guage doesn't work I swapped out the cluster so I am thinking it is the sending unit in the tank. thing is on the way home tonight my light came on telling me I am low on fuel. does anyone know why the light would work and not the actual guage? I would have thought they would be off the same sending unit.
my car is AWD so the sending unit is hard to find. and dont wanna pay alot for one if it could possibly be something else.

 

[luv2rallye]

Low fuel light has separate sensors in the tank (on the same fuel level connector).

You can ground the all yellow wire on the driver's side fuel gauge connector and the gauge should read full.