Vw golf mk4 horn

Hi can anyone help I have a mk4 golf 2002 1.9 and the horn will not work. Taken it off and tested it and it works. Checked and changed the fuse. The air bag had blown I have changed that and the part below it, the ribbon. Got nothing passing the fuse when tested with a meter while holding down the horn. Any ideas would be great. Cheers.