Auto wipers and snow

[Thackeray]

Does anyone know if the auto wipers have some sort of protection from damaging the mechanism when the wipers can't move?

Now that the snow has arrived, I'm wondering what the wipers will do if the car is covered with snow and you turn on the ignition. if the windscreen is covered with thick snow, I would expect the wiper sensor to respond by activating the wipers. But if the wipers are frozen solid to the windscreen that presumably has the potential to cause some damage to the wipers, mechanism, motor or all three. Maybe Lexus have thought of this and incorporated some sort of safety mechanism to prevent damage. But the manual doesn't say anything about it as far as I can see.

Does anyone know the answer?

In the meantime, I've been leaving the auto wipers disabled during the cold weather. Is that an unnecessary precaution?

[Rabbers]

If you have snow or ice on the windscreen and have left the wiper switch on AUTO, the wipers will respond one or two seconds after ignition unless

you use this time-lapse to switch to manual control.   The lapse is short but more than sufficient to allow you to simply press the end of the wiper 

stalk.

[Mr Vlad]

Just turn the auto function off when you park up for the night.

[Texas]

Wiper motor circuits ( front anyway ) are normally 'fused' with a miniature self resetting circuit breaker type fuse. Not sure if they are on your particular model but this is so if the wipers are in fact frozen to the windscreen then the motor will draw a large amount of current trying to shift them and if it was a normal fuse the fuse would blow and then after the ice had thawed the wipers would not work! But with the circuit breaker the high current flow trips the breaker and after a few minutes it cool and resets.

Pic here in post #24 http://www.talkford.com/community/topic/318786-electrical-help-needed/page-3

paul m.

[Thackeray]

1 hour ago, Texas said:

with the circuit breaker the high current flow trips the breaker and after a few minutes it cool and resets.

Pic here in post #24 http://www.talkford.com/community/topic/318786-electrical-help-needed/page-3

That's interesting. Never knew that. I suppose if you find the relevant fuse it would be possible to tell if this is installed on the IS300h just by looking at it. Perhaps I'll do that when the weather isn't so cold. I don't want to be fiddling about with fuses with ice-cold hands!

In the meantime, maybe somebody already knows if the IS300h has resettable circuit breakers on the windscreen wiper circuits. That will be useful to know if someone else has already checked!

[PaulWhitt20]

Another option is to check the wipers are not frozen before you get in the car. Also to get the snow off the top of the doors before you open them and the snow falls on the seat!.

One not so easy to check before it is too late is if the window is frozen. When you put the window down and its stuck, will that do any damage?

 

[J Henderson]

4 hours ago, Mr Vlad said:

Just turn the auto function off when you park up for the night.

This. Ditto for folding mirrors, if equipped.

[daflux]

On the subject of visibility: Does anyone else think heated washer jets wouldn't have gone amiss for a luxury car brand?

[NemesisUK]

Mercs get heated nozzles, some even heated washer fluid reservoirs. The door mirrors are heated automatically at temps below 12c, great for drying off rain/condensation.

So, Lexus offer heated wipers (screen heated under the parked wiper) but no heated washer nozzles?

Must admit hadn't noticed the lack of heated nozzles, my screen wash has been working fine the last few days.. 

[rayaans]

You only need heated washer nozzles if your screenwash is rubbish.

The original Toyota stuff is rated down to -70 degrees so you shouldn't have any issues.

[Thackeray]

Oddly enough, going out in the snow today the windscreen wipers weren't frozen to the screen. But when I tried the washers after a while - nothing happened. They were frozen. (Has someone been diluting my screenwash?) Heated nozzles would have been handy.

When I got back home I had another go. The interesting thing was that after the initial whirring you get from the screenwasher it went silent. No matter how much I pulled the wiper stalk there was no whirring noise. Could it have been one of these automatically resetting circuit breakers mentioned above? 

Anyway I poured some cold water on the nozzles in the hope of unfreezing them. Then I tried again after an interval. The whirring noise was back (had the circuit breakers reset?) and the washers were now working.

Finally, I topped up the reservoir with some more antifreeze screenwash - let's hope it doesn't happen again.

[TBi]

This is one thing i miss about my BMW. It turned off the auto wipers when you locked the car, so no worry about this happening. 

[steveledzep]

1 hour ago, TBi said:

This is one thing i miss about my BMW. It turned off the auto wipers when you locked the car, so no worry about this happening. 

Trouble with that is you have to remember to switch auto wipers back on......every day of the year !

I'd rather remember to deactivate just on the occasions that frost or snow is expected.  If there's frost or snow, I deactivate auto wipers in the morning, before I switch on.  Far better than having to remember to reactivate every day of the year !!

[NemesisUK]

Surely the auto part of the function is the variable speed of operation. Switching them on/off is still manual.

I'd second the function resetting on cycling the IGN. It's painful when the wipers sweep across a dry screen...

[Thackeray]

On 02/03/2018 at 6:01 PM, NemesisUK said:

Surely the auto part of the function is the variable speed of operation. Switching them on/off is still manual.

Maybe I've misunderstood what you're saying. But my original point at the top of the thread was that on the IS300h when the wipers are on auto they turn themselves on and off automatically. (They also vary speed automatically.) My concern was what happened when they turned themselves on automatically and the wipers were frozen to the screen.

One answer is to turn off the auto setting before the snow comes. 

But are you saying you have auto wipers but they don't turn on automatically?

[ColinBarber]

If you leave the auto on then part of the rubbers will get ripped off if the wipers engage when you turn on the ignition if the rubber is partially frozen. If it is completely frozen then you may trip the breaker/fuse.

Either remember to turn off the auto wipers or remember to free the wipers before you get in.

 

In freezing weather it is also advisable to turn off the folding mirror function otherwise they may get frozen shut (happened to me a couple of times on my IS).

[Farqui]

Be very careful leaving auto wipers ON in winter as some vehicles are known blow ECU's not just fuses.

Which is bonkers as the fuses should protect the electronics.

[NemesisUK]

3 hours ago, Thackeray said:

Maybe I've misunderstood what you're saying. But my original point at the top of the thread was that on the IS300h when the wipers are on auto they turn themselves on and off automatically. (They also vary speed automatically.) My concern was what happened when they turned themselves on automatically and the wipers were frozen to the screen.

One answer is to turn off the auto setting before the snow comes. 

But are you saying you have auto wipers but they don't turn on automatically?

No, I'm saying turning the function on and off is a driver responsible action. The operation during a drive is automatic, speed, stopping and starting..

[NemesisUK]

1 hour ago, ColinBarber said:

Either remember to turn off the auto wipers or remember to free the wipers before you get in.

 

Or just remember to turn them off before switching the IGN off

[TBi]

On 3/3/2018 at 11:32 PM, NemesisUK said:

Or just remember to turn them off before switching the IGN off

I prefer to have to turn them on manually, if it starts raining (not every day of the year), than panicking when they wipe across a frozen screen. I'm not the only person who drives the car and can't always guarantee that they turned off the wipers. Plus it's not the first thing i think of when i get in the car and shouldn't be either.

All my BMW's worked this way and i prefer it to the way lexus works. Would be nice to have an option i could set to match BMW.