Well I attacked the leak again today, removed harness cover and resealed it, the seal under the box and the seal on the lid of the box were both damaged, hopefully it is sorted now.
Just got to wait for it to dry out as it is soaking now due to all my investigating with the hose pipe
Here are pics that will hopefully help someone else
harness cover with wiper linkage removed and lid off

harness unplugged and box removed
