The battery may leak acid at the battery cable connections. As a result corrosion may form on the battery cable ends. Leaking batteries should be replaced and the cables need to be thoroughly cleaned or replaced if necessary.Google+
Car Problem Reports
Cadillac Seville STS Corrosion on Battery Cable Ends
Cadillac Seville STS Problem
Visitor, 2001 Cadillac Seville STS, 42,000 mi
The connection to the fuse box under the hood gets corroded and looses its connection. Even after replacing the fuse box.