mbh

And just to close the loop on this one. Black and yellow wire from relay K14 to the two horn sounders does go +Ve on horn press but doesn't reach 12v. It will readily switch a relay though.

Every so often I will spend days scratching my head and and getting frustrated before I remember to check on here. One again this is *exactly* the problem that's confused me for a week. Will change tack and try the above 🙏