The screen washer works perfectly on the passenger side, but only gives a spit from the driver side jets. The rear washer works too. Suspecting a blockage, I poked a good couple of inches of thin plastic "wire" into each jet, but made no difference. The washer bottle is full.

Can anyone explain proper function on one side, but nothing worth bothering with on the other?

What can I do?

It is a Ford Modeo Zetec 2.0L Diesel, UK built in 2009 with a 58 plate.

Thanks...

As you say it's blocked somewhere, I'd pull of the pipe and give a good clean or it may just be the nozzle that's blocked.

Thanks pragmatix. Definitely not the nozzles, so any blockage must be must be the pipe...

Thanks to pragmatix for the clue. It turns out that the pipe to the nozzles in only 2" long, separated from the main pipe by a non-return valve. That value was completely clogged, as consists of a spring loaded mechanism inside a hard plastic tube. I now have a screen wash on the driver's side.

I hope this is of use to someone else in future.