trumpet1

I know there was a previous thread discussing this but I can't find it. Just this week , my car started doing what some have complained of in the past and that is a single wipe of the wipers after giving a left turn signal , stopping, and then turning left. As soon as the stalk returns to the middle position as I complete my left turn, I get a single windshield wipe. And then tonight it even happened after making a right turn!! Did anyone figure out the remedy for this? For now, I'm just going to turn my wiper switch to completely "OFF" (no intermittent position selected) and live with it.

chipps

You and my wife are pressing in slightly on the switch when you use it as a turn single. This causes the wipers to wipe once.

trumpet1

No. That's not it, at least in my case. I'm not touching the stalk when it happens and I've had my car for two years and this wouldn't be something I'd just suddenly start causing from user error. Others have reported it and there is apparently a kink or short in the wiring most likely.

Giving a turn signal sets up the problem (like cocking a gun), then as the wheel turns back to straight, it must be pulling on the switch/wire in some way to trick the mechanism into thinking I pressed inward for a single wipe.
I'm going to wait and see if keeping the wiper system turned completely off settles it temporarily. If it still does it, then my theory is most likely correct.

Diesel Benz

I know trumpet1 would not make a mistake with this new car when operating the stalk while having so much experience from a V221 (fine for chipps to mention that option though).

I do remember one owner reporting wipers activating when turning but I thought it was always only when turning to one direction only, and I don't remember if he was using the blinker at all.

Anyway the wiring issue was for very early cars and even there a guess from the fact that the wiring issue may confuse some CAN-bus signalling.

A bad stalk would be an option but of course a bit odd for a car this new.

EinMD

I have had the same issue occasionally, most recently a few days ago while making a left turn. Having read the previous post on this issue, I immediately checked the stalk and found it was in the 1st auto position. I don't know what caused it to happen either as it was not raining.

Diesel Benz

The rain sensor may trigger wipers from some odd external light/IR reflection even if it was not raining but this could happen when driving straight too, I guess you did not have a direct sunlight coming or going when turning or something like that?

Can you clarify your experience, was it "just a left turn" or was it when you moved the stalk to blink left? Or did you you use the blinker at all?

trumpet1

The way it happens to me is usually right after I start the car and go down the street, I approach my first left turn that I have to make, I give a left turn signal , approach the intersection while turn signal is blinking, I stop at the intersection, I make the left turn, and within a second after the turn signal stalk returns to the middle position and the turn signal is no longer blinking, the wiper sweeps once and only once. I have , so far, noticed it only while the setting of the wipers is in the first intermittent position.

This same thing happens as I leave work and head for home. It seems to be right after a start cycle, happens once after that start cycle and then doesn't happen again. This same thing happened just after making a right turn Thursday.
As of now, I have the wiper switch in "OFF" and it hasn't happened YET.
All of this just started happening last week.

EinMD

I would say Trumpet1 explained it exactly like my experience. In response to Diesel Benz's question to me, it was early evening and dark already. My belief is that I must be lightly hitting the stalk causing one swipe.

tomd

Count me in with my 09. a single swipe. 1/200 left hand turns. 1/500 right hand turns. I am not touching the stalk at the time. odd.

trumpet1

I'm not going to worry about it. Mine hasn't done it the past two days. Until it becomes a major problem, I would rather just live with it. Right now, I have a headlight flickering that is more of a major problem. I'm going in Friday for Schedule C work to be done.

valiumvilla

As I understand it, the "auto" wiper function is not designed to be left on all of the time. According to the owners manual it should be turned "off" unless you are expecting to use it as in rain or snow at the current moment. It functions with an infrared beam and can potentially burn out thus the manual on and off routine. I leave mine off unless I run into weather requiring the need and try to remember to turn it off......which doesn't always work and I forget.
I agree with others about the reason for periodic single swipes of the wiper.

trumpet1

Hey man, thanks. I'll just leave mine off like you recommend. Hope I haven't done any damage

Diesel Benz

Can you post a pointer to that manual section, or copy the text here? If it has the advice to turn auto mode off, that must be for safety and even more liability (a sudden wiper operation blocked visibility at a critical point and the driver did not see a house approaching the car ).

The IR sensors probably do age, but nothing significant, at some places you have to keep wipers on auto most of the time anyway and the car is designed to survive from that. Perhaps you can avoid sensor service after a few hundred thousand miles when not keeping it always on. But in my opinion, switching auto mode off is more useful to avoid sudden wiper activation from odd light reflections etc.

valiumvilla

The recommendation for turning off the intermittant function can be found on page 371 in paragraph 2,3, and 4 in the first column on that page in the Operators Manual for the S class model. It has to do primarily with not causing damage to the windshield and wipers in dry conditions associated with a false triggering of the wipers.

Diesel Benz

Now I did find the text you were referring, on a different page though of my pdf copy. As you say, the manual even mentions the possible damage to the windshield.

This sort of almost allows me to ask an off topic but related question that I've asked before but have not seen comments: if I have not used windshield washers for some time, the water seems to drain off from the washer pipes slowly, it then takes some time when I flush the window before I get water sprayed, the wiper tends to make a full one way move before water is sprayed. Just like there should be a back-pressure valve but it is leaking. Anyone else having an issue like this?

I guess I should study the parts, could be some debris at the valve, if there is one.