Thought that the buzzing is caused from a faulty earth.

So i earthed a piece of wire and turned ignition and lights on and put the earthed bit of wire into the earth connection on the blue relay and the buzzing stops which suggests its a poor earth somewhere?

Have redone some of the earths in the bay but still no luck.
Is there anyway i can test the earths to see if there okay and working?

Is there anything else i can try? Really struggling now