I didn't disconnect the battery before starting to remove altenator and caused the cable to spark when removed. After installing

 

What?

 

I wasn't able to finish, but after installing the new altenator, car started but nothing else works. locked in park and lots of lights in dash on..mechanic says power to computer (ecu), but no power going out.Was Able to release from park and drive to shop, no lights or any accessories working??? Unless there is another fuse or link, may have fried the ecu??

 

What year of car and engine type 4-cyl or V-6?

The computer operates the engine and trans. If the engine and trans work OK, the computer should be OK.

After the battery, the electrical system splits up.

Check the 100 amp alternator fuse.