[Philkwill]

I try to run my tank out to make the gas low light come on. Nothing! Is there one?

 

[humanoid]

What year is your truck?

 

[TuRDle]

Put a two gallon container of gas in your bed and drive until your truck stops running. If you don't see a light when it happens you don't have one. Also look for a little gas pump logo next to your gas gage. If you have one it will light up when you get low on petrol.