I have a 2001 golf jetta an I just replaced the alternator an it worked for a week but now it wont even turn over what do I do to get it started?

Bad battery maybe, or maybe there's a short somewhere in charging system

It was eatin batteries like crazy an quit but all my lights work still. Does it gotta pull power from the battery to turn the starte?I have done replaced a few things. Could it be a ground somewhere an if so how would I know?

Use a multi-meterm - Turn the multimeter settings knob to "continuity." The continuity setting is indicated by a small microphone symbol. This setting tests the amount of ohms at one end of a wire in relation to the ohms discharged from the other end. Unequal ohms measurements are evidence of a short in the wire. Place the negative multimeter probe, the black one, on one end of the wire you want to test for continuity. Place the red probe, the positive one, on the other end of the wire. Listen for a sustained beep, which indicates continuity.Look at the monitor on the multimeter. Check the number of ohms displayed on the screen. Continuity requires at least .3 ohms. If the screen displays a smaller number, check the wire for breaks and frays.