battery charge

I have a 1998 Jaguar XK8 with 93k miles and a 4.0 liter engine. I replaced the alternator today and the battery wont hold a charge. What should I do now? Is there a fuse I need to check? The old alternator was tested and it was bad. Do you have a wiring diagram to make sure I have the wires on the correct leads?
Please help....