Electrical problems?

[98v6]

I drive a 1998 v6 non y87 charmeleon firebird.

My alarm has started giving me problems, i set it with my handset and it goes off randomly after that, why? i have no clue but it is to the point that i just don't set it any more.

yesterday i had to replace my alternator and today i put my freshly charged battery on and started up the car, unlocked the stereo and... nothing. it just said SEC on the display i couldn't turn it on, eject the cd... anything. and when i left church to drive home, the display lit up but nothing showed. it was just orange light.

plz help! & thx in advance

[mcjoslyn]

I think you'll find you security locked the head unit when you pulled the battery. I don't know about yours for sure, but a lot of the GM units require a security code to unlock them when they lose power. Check your owner's manual and hope that no one has changed the code.