We might have some ideas if you show us the script.

But some options are:
- You say the script produces output, where is this output send? To a file or to the screen? If it is the screen the script will not work because there is no tty attached to t.
- A cron job runs by default with a very limited PATH environment variable. So if you don't define PATH inisde your script correctly, or use all commands with their full pah name, it could be that 1 or more commands cannot be located and therefore result in an error, which cause your script to terminate.