My grande punto back window wiper has stopped working, the washer still sprays water but the wiper doesn't go, I've tried connecting another motor and changing the fuse but still no joy, anyone else had this problem or know what it could be?

Obviously power is either not getting to the motor or not getting from the motor back to ground, you need a multimeter to check you have power on the plugs into the motor and to see if the earth is any good

I remember a post somewhere (can't immediately find it) about the wires to the wiper. Try tracing the wiring back and in particular check them where they go into the body

Raise the tailgate, in the top left hand corner is a rubber boot.
The wiper wires run through there and will have no doubt rubbed through or broken.

The punto ive just bought had the same issue plus the washer wasn't getting any water and as above it was a snapped wire(big brown one) and the washer pipe was split under the rubber boot.

I have just had the same problem, I had 3 split wires and the washer hose was cut.