when you oush the horn button you can hear it whirring but not the 130 dB I need
Any bright ideas would be appreciated
Thanks
Is there anything touching it (frame, wire, etc)? Might be dirty inside as well.
My guess is that you didn't use a relay. Just stuck the tiny little stock horn wires to it, robbing it of enough amperage to spool the fan fast enough to move the diaphragm.
Pictures or a better explanation could help you get better responses next time.