Nissan altima replace battery but music wont work

Ur car has an antitheft device get that checked or just pull fuse and putback in .

Right next to the battery, there's a black box with fuses in there.
Check the top red clear one. I bet that is the problem.

It depends on the year if its a newer altima the stock radio will have an anti theft warning if you disconnect the battery the radio thinks its being stolen and locks up you have to call your dealer they will either give you the pass code or tell you how to get ahold of it next time you change the battery remember that they make setting savers that go into your cigarette lighter so you dont have this problem i know autozone has them hope this helps