Rear wiper and washer wiring

[land864]

Having had the Cargo door lining off recently I noticed that the 3 black ( earth? ) wires had broken off the lug and were not connected.
The wiper and washer run without these hoked up, are they necessary?

[Psimpson7]

I would recconnect them. It is probably earthing through something else which it shouldnt be, and may cause other issues.