89 astro wont start

I went to the music store, boght my self i guitar, came back to the car and tried to start it. i tried a a few times and nothing. all of a sudden it started. got back home with no more problems but once i tried to start again it wont go. All i rear when i tried to start my car is a big click noise.
I changed the battery about one month ago. I need help because i work with this car. Hope somebody can.

you should check your battery connections, i had the same problem, bought a new battery and everything, then found out that my ground wire to the body was loose!!

you should check your battery connections, i had the same problem, bought a new battery and everything, then found out that my ground wire to the body was loose!!

I checked and it was good. It was the starter. Thanks