Fiat Punto 2001 1.25 electrical problem?

Hi
Mi fiat punto has a big electrical fault.
The back wiper is on all the time even with the key out of ignition. same with allt the orange lights.
The majority of electrics are not working in the car like heater blower, headlights, front wipers.
I have found that by removing the fuse for the windscreen / rear screen washer is puting the wiper and orange lights off. However when atempting to turn on heater , or headlights the back wiper comes on again.
I suspect that there is a short circuit in the washer pump somewher but not sure where to start.
Thanks