I had similar symptoms on my 98 V70 and it turned out to be a clogged check valve. This check valve is just before the nozzle and you do need to remove the upper interior door trim to get at it. Of course I broke half of the clips and the trim is still lying on my workbench. I bought a replacement check valve on e-bay.

There is a way to access the plumbing just before it gets to the door. If you open up the speaker cover at the very back of the car on the right side, you'll see washer hose and a connector. You could open it up and see if the fluid is flowing up to that point.