Why does my starter sound weak and my battery goes dead?

If you have done all those tests and no answer yet. I will advise to disconnect the batterie at night time for a few days and if the car starts fine after a few days after connecting the batterie in the morning you have something sucking the juice from the batterie,now the tricky part its to find whats causing the problem. But remember allot times the batteries even having the NEW tag name sometimes they are in storage for along time and they dont keep the charge as good.

Been there done that also. I know I have a draw down, but why does it not charge back up after driving it? I didn't just try one thing once, I have put two starters, two alternators, and 4 batteries, I am a mechanic. But this has me stumped. Any other suggestions???

You have to find what is drawing the power,as saomi,said,this will be the only fix to your problem,with engine off,check the power draw on,the battery,then you will have to track it down,there is something still drawing power,and could be your igntion it,self.

I put a starter in my car a alternator and battery in my 2000 Cadillac dts and still want start

Check all the ground wires or add a extra ground from the body to the engine block that fix my car