Don’t see if this has been asked m o t

[geoberni]

My enquiry was around whether it gave any further detail anywhere??

The MOT Tester (who will have been watched and assessed by a VOSA officer) simply activates the washers & wipers. All the wipers have to do is clear the screen without smearing or otherwise impeding vision. All modern vehicles activate wipers when the washers are used and if the screen is cleared, that is all you need. There's no requirement to check speeds or other settings.
As in most MOT things like that, things are approached as if the operator has no knowledge of a particular vehicles foibles.
In that testers opinion the wipers failed because they could not clear the screen as they didn't move when switched on, and the tester has the final authority as an agent of the Ministry of Transport.
It would have created a danger if the screen has been obscured by something suddenly landing on it, a spattering of mud, or a big bird poo, so I had no issues with the decision.

Thanks for the explanation, but I don't get the failure with a dry screen. No wiper is going to clear a dry screen, especially in the examples you give of mud or bird poo, it's simply going to spread it and make vision worse.

Back to my original point, are you saying there is now no documented procedure laid down, i.e. as in the 2012 example I posted earlier where it says :

Method of Inspection
Operate Washer and Wiper...

I wonder how a modern day Tester copes with vehicles fitted with Vacuum Wipers, which didn't finally stop being fitted to some vehicles until about 1970... MOT on a post war Ford Prefect anyone, although I guess that would be exempt, so long as the Tester notices it has an opening windscreen...

[exlkrs]

This is getting daft now. Forget wet or dry (if your flick your wipers on by accident, they work.). Tester flicks switch, nowt happens, end of story. I suspect a little mischief is afoot here, just for the sake of it!!

[geoberni]

This is getting daft now. Forget wet or dry (if your flick your wipers on by accident, they work.). Tester flicks switch, nowt happens, end of story. I suspect a little mischief is afoot here, just for the sake of it!!

If you're not interested, move on .....

[exlkrs]

This is getting daft now. Forget wet or dry (if your flick your wipers on by accident, they work.). Tester flicks switch, nowt happens, end of story. I suspect a little mischief is afoot here, just for the sake of it!!

If you're not interested, move on .....

I have! As I said, 'end of story'.

[olonas]

"I wonder how a modern day Tester copes with vehicles fitted with Vacuum Wipers"
Or a foot operated dipswitch. There was a story, some years ago and never verified, that a young tester broke off a Minor's indicator stalk when trying to dip/main beam it's headlights!

[Bill_qaz]

I once had a young mot tester lying down with a torch looking for the E stamp on my motorcycle silencer. Never found it on a 1952 AJS

[Guildbass]

Thanks for the explanation, but I don't get the failure with a dry screen. No wiper is going to clear a dry screen, especially in the examples you give of mud or bird poo, it's simply going to spread it and make vision worse.

Back to my original point, are you saying there is now no documented procedure laid down, i.e. as in the 2012 example I posted earlier where it says :

Method of Inspection
Operate Washer and Wiper...

I wonder how a modern day Tester copes with vehicles fitted with Vacuum Wipers, which didn't finally stop being fitted to some vehicles until about 1970... MOT on a post war Ford Prefect anyone, although I guess that would be exempt, so long as the Tester notices it has an opening windscreen...

With the mud or bird poo, you active the wipers and either the screen wash starts, or in our case, you pump the washer to add water to dilute and move the dirt. Either way, the wipers may well start on a dry screen!

With a vacuum powered system, you run the engine if that's what is required. The test allows for the idiosyncratic methods on older vehicles. Sometimes a Tester needs to be helped. In the case of that Traveller it was to be told where the main beam switch was!
Yes, folding screens don't require wipers to be present !
There are sometimes strange anomalies...Like on some vehicles, the third brake light is not part of the lighting to be tested as a brake light, yet has to function if fitted so can be obscured and then the car passes!