My rear windscreen heater and wiper only work intermittently. At first it would seem quite random as to when they would work (i.e. They would start working part way through a journey, or at the start or not at all!) but I've noticed that the carpet in my boot is very wet during rainy weather and creating excess condensation.

Is it possible that the rain is affecting the electrics and the wipers and heater only work when it's a bit drier?

How can I find out where the leak is and prevent it? The parcel shelf is dry and so are the rear seats.

Please help!!!

Mat