s-10 alternator replacement now won't start

Replaced the alternator on my 1994 S-10 pickup this morning, after installation completed tried to start the truck and got only clicking. Thought it might be the battery, called AAA when the truck is jumped it just cranks but won't start. Can anyone help a middle aged lady out?

Without knowing any more I'd guess the low voltage blew a fuse, maybe in the fuel pump circuit? Check all fuses.