1994 buick roadmaster on 1994 Buick Roadmaster

I have a 1994 Buick Roadmaster, a few days ago I noticed when I was driving the stereo would turn off but then turn on a few seconds later. I thought I would have to to replace the battery. Yesterday it completely died, it sounded like it wanted to turn over but didnt followed by a clicking sound then nothing. Is it the starter? or the battery?

Asked by for the 1994 Buick Roadmaster
test the battery terminal voltage which needs to be at least 12.6 volts. Then if that is 12.6 or more, then check that the starter is getting a good trigger signal from the ignition switch, if it is, then the starter may be defective. if the battery is low and over 4 years old, replace it and then check your alternator output. if your battery is new, then charge it up and then check your alternator output. These are a few of the basic checks I would perform for your problem if your car was in my shop.
I had very similar problem last year on my 1994 roadmaster-turned out to be related to the"VATS" system