When i start the tundra, on higher rpm's its allright
when rpm's are lower it shows batery sighn on and off, if i rave it a little sighn is off, after little wile dont matter how hard you rav it it does not churge the batery, at any time when i would unplog the batery cable truck would turn off

 

Change the battery

 

Your battery will be expired that is why such problem will be creating just change the battery.

 

Firstly make sure that all the cable's are fixed and attached properly or not loosened. If the problem still persist then there must be something wrong with your charger of battery.

 

I think you should change your battery.