From: Harry Bloomfield on
Ian Jackson has brought this to us :
> That's fine, unless it's one of one of those occasions when you don't want
> the wipers to operate.

I can only think of in a car wash where you would not want them to

> I've only been half-following this thread. Do you always have the option of
> keeping the automatic wipers turned off?

My switch has four positions - off, auto, manual slow, manual fast,
with a sensitivity adjustment on its end. I have not actually found a
use for the sensitivity adjustment yet.

Off is off, no wipers at all. Auto - wipes when ever the screen is wet/
needs to be wiped. Slow and fast - work as for normal manual.

So the auto takes the place of what is usually the intermitant switch
position. I just leave it always set on auto, wet or dry, but auto
cancels if you switch the ignition off, so if it is raining or starting
to rain I would need to move it to off, then back to auto for them to
work. The same (I think) applies to slow and fast, so that if the
blades are frozen to the screen you have to take some action before
they will run.

So basically you just forget the wipers once on the auto position and
your screen is always cleared the instant water appears on it, with no
delay and no wiping when it is not needed. It does a far better job
than I could do operating the switch manually.

Harry (M1BYT) (L)

From: Harry Bloomfield on
Adrian explained on 06/07/2010 :
> Auto-wipers? How do they do that, then, given that the sensor works from
> the change in internal reflection caused by the water on the glass?

I would guess at something like that. Between interior mirror and
screen is a little box containing the sensor, nothing at all on the

Harry (M1BYT) (L)

From: Harry Bloomfield on
Mike Barnes presented the following explanation :
> We all know that accidents, near misses, and simple poor driving often
> occur due to a combination of factors rather than anything in isolation.
> A small distraction can tip the balance.

Quite so!

I think we have all been in situations on the road where one thing
which needs our attention has distracted us from something else which
is equally demanding. The same applies to actual vehicle controls - the
more that is done for me, the more of my attention I can keep on the

Old basic cars were fine on old basic roads with not much traffic, but
things have changed - much faster, less patience shown, more complex
situations and much busier.

Harry (M1BYT) (L)

From: Harry Bloomfield on
Adrian brought next idea :
> You need to think about it?

Well some thought process has to be involved, even if the reaction is
automatic, so there is a variable delay between need and action. The
automatic ones just react instantly to the need with no process
involvement from the driver.

I also tend to not notice so instantly, (or if I do, delay until it is
safer to reach for the switch) that the rain has stopped and to turn
them off. With automatic wipers that never happens, they are never left

Harry (M1BYT) (L)

From: Harry Bloomfield on
Mortimer wrote on 06/07/2010 :
> How do you define the delay for variable-speed intermittent? I've always
> wondered how this is done, having only ever driven cars with two-speed
> continuous (plus flick-wipe) or else fixed intermittent or auto wipe.

My old car had a twelve speed delay and what I did with that was
continuously adjust it to account for the variations in the speed that
the rain was falling. Once on minimum delay, the next stage is to move
onto slow, then fast.

Harry (M1BYT) (L)