electrical probl;ems

we have a 1996 diesel jetta that seems to lately have strange things happening with the electrical systems involving mostly the radio, the alarm system and the power door locks as well as the cruise control. the radio goes into safe mode after the doors are locked and the alarm goes off the alarm goes off after the doors are locked with the keys in either front door and the the back doors or trunk is closed the doors will not always lock and will not always lock from the inside switch and the cruise control works only every once and a while . this was the first problem we had and the others have slowly developed over the last

does anyone have any suggestions as where to look i have not checked any of the electrical sysytem yet but i am going to check the battery and ground and check the fuse and relay panel for any loose fuses and or relays any other isdeas . i will check anything that anyone suggests .or if anyone has a web site that may haelp

thanks in advance

john harrison