OK, let's get the basics: what is the exact error message you are getting? Post a copy of the message (which may be more than one line, by the way) -- don't try to paraphrase it. If the job does not have a //SYSUDUMP DD SYSOUT=* in it, you'll need to rerun the job with this line to get a dump. The dump includes all the program WORKING-STORAGE which presumably will tell you exactly which record was being processed when the problem occurred.
Also, check with your coworkers to see if Abend Aid is installed at your site -- it is an error analysis tool that will simplify your problem fixing by pinpointing the precise problem and its location.