No power to windscreen wipers

Hi there,
My windscreen wipers stopped working as well as my direction indicators. I noticed my ammeter is also showing a negative charge whilst running and a positive charge when ticking over…this all happened out of the blue they were working fine yesterday! All the other electrics are fine
Any ideas??
Thanks scott

My ideas:
The fuse between A3 and A4 is blown.
The cutout points in the regulator are stuck closed.