My screen Wipers have suddenly go on the go slow, worked fine last week,

Anything obvious to check or common problems

Linkage is probably seizing up, very common.

Get a new linkage, not to expensive.

I would suspect the linkage - is the motion slow or slow and bit a juddery?

Otherwise might be worth checking the earthing, as a poor connection could reduce the amount of power available for the wiper motor.

There judder and there slow even with wipers picked up off screen, they do about 4 slow sweeps then trip off,

Is there earth under scuttle panel

Seized linkage for sure

Seized linkage for sure

I agree.

If it was me, I would take the linkage out and up where the spindles pass up through the bushes and pack with grease. I did that about 5 years ago on mine, and they have been faultless since.

Wiper motor and rack out of the car, this is off a 2002 Octavia

what you see once stripped out, circlip, washer underneath, rubber O ring [rack housing] washer at the base and the crank itself.

On this one there was a bush at each end of the housing, between the bushes there was alloy corrosion packing the shaft so tightly it was seizing, you can see the crud below in the pic.

It took 10 mins to get one crank out, the other took 30 mins in a vice winding backwards and forwards while exerting pressure to get the shaft out. Loads of penetration fluid from both ends, but the powdery corrosion was bone dry once the cranks were out. I have 3 racks here all were seized to some extent or other.

I reassembled the cranks coated in grease.

Don't be tempted to hit the wiper arm threads with a hammer, you'll never get the nuts back on.

Sprayed it with abit of wd40 at lunch just down wiper arms and they work fine now, so they were seizing up,

Job for weekend now stripping all wiper mechanism off and stripping down and cleaning up

You'll need a well mounted vice to get the cranks out, the pic of the crank was taken after it was cleaned with emery