A very popular local repeater does a Morse ID every 15 minutes or so on 467.575.
The Morse decoder is probably your best bet.
Couple of other things:
Are you hearing any voice traffic, or just the Morse ID every 15 minutes screaming into the ether?
How is your GMRS radio set up? Do you have it programmed to properly transmit on the 467.575MHz frequency and receive on 462.575?
If you don't have the correct PL/DPL tones for the repeater, it's possible they will not hear you.
Do you have a scanner that will decode PL/DPL codes?
-It's possible that input and output may have different codes, so the PL/DPL transmitted by the repeater may not be the same as the one on the receive side.
Some repeaters are just not open to other users and won't share information. If you run into a brick wall, you might be out of luck.