93 passat glx

So I have a 93 passat glx and I try to get in
the cat and start it and won't turn over the
car is completely drained. So I jump the
car with an auxirally battery pack. And as
soon as the car is running it's fine I can
leave it running for 4 hours and it won't
die. But until I turn the car off and take the
key out of the ignition and I go back to
start the car. It's completely dead. And I
just bought a new battery so I know it's
not that. I tried to check my fuses and
even had someone check my wires
relating to the amp and speakers and also
the car alarm which he claimed he
disabled and they redid the wired for my
speakers but yet I still have the problem.
Any ideas?