Welcome to the club jam136. I had that problem and what it was , was that there is a wire that goes into the windscreen and it attaches to what is like a little black box whitch then attaches to the wiring that connects to the wiring on the car. These are on either side of the windscreen and what happend wasthe wirefrom the windscreenhad broke off the little black box shaped object on the one side meaning that only half my windscreen worked. I dont know if this is the case for you but it was for me and I neeed a new windscreen.