Ford Transit Courier weird noise

[Wayne Hawkridge]

I hope someone can help with a problem with my 1:5 transit courier which is on 192000 well in the mornings it starts really good but when u stop at a junction at the end of my road it starts making this odd sound like a horn it only lasts for 10 second and it will do it every time I stop for about 10 minutes then it goes and doesn’t do it again till the next morning it’s very frustrating cause no one can find out why it doing it no dashboard lights come one no faults when it connects it up to a computer so was wondering if it has happened to someone else I appreciate any help I can get thanks