Screen wash only on back windscreen

can you hear the pump when operated if not then the screen wash pump may be k put and need replacing but also check fuses and if you can check connectoions to the pump just to make sure there is a good connection

If the rear is working , pump must be operating .Usually blockage at pump / connection where there are two .Could just be needing gunk , soap cleared out .

Agree that pump gauze is possibly choked or even pipe may be off.

put new pump it has a slideing valve in it they jam up and only the rear works swop pipe around as a temp fix and use rear wash to clean front farely easy to get to just pushs into bottle loads of pumps on ebay cheap