ok so i plan on changing my alternator. ive been getting some extremely week starts so i took it up to orielly's and a guy ran a check on the battery and the alternator. He said to put a new all alternator on and see if the place where i got the battery from a year ago will cover it with warranty. He said the lights and amp killed the battery which in turn killed my alternator. does this sound rite?

Also any things i should know before replacing the alternator?

 

A dying battery can put lots of strain on your alternator, however; your alternator usually works or it doesn't. rarely do you get intermediate charges.
I would change the battery FIRST and see if that solves your problem.

 

in the mornings ia when its worst and right after he ran the battery test it was like it barely starts and u have to stay in the gas at first to keep it running but when i go to school and come out it starts pretty easy. But i think if i take to walmart where i got the battery from theyll say its the alternator and not cover the battery at all?

 

You need to remove the battery and have it load tested. Sounds like a couple cells are not holding a charge.

if you have a voltmemter go start your truck and let it idle for 5minutes. Then turn it off. measure the voltage of the battery. if it's under 12.4v then you need to replace it. HERE is a link to reference