Seagull36

Sorry forgot to mention its a berlingo 1.6 hdi 2012 plate with 32k on clock

my horn keeps going off every so often for about 30 seconds until i could get key in the ignition and engine started, even then its still blaring. If I leave it without starting it up it beeps a single beep every minute.It's had a new battery I've tried the bsi reset, but nothing's changed, also tried a battery drain test and only uses 10milli amps. Anyone came across this before?