I have a honda GL1500 with builtin radio system. similar problem to reader befor radio is on BUT no volume its as if the mutt switch was stuck intercome to helmits works fine. all fusses are good that i can seewhat else can I do besides replacing the whole radio?

Make sure the speed volume controls and speaker, headset controls are also in the correct postion. If no joy with that by pass the mute switch by hot wiring around it and see if you get volume. Check connections on the wires to the speakers etc. Probably something in the connections to the speakers/headsets.

Sometimes a cb problem causes this, try unplugging the harness to the cb.