Wipers Switch Operation

[Pawel66]

Could not find this detail of wiper switch operation with "Search" so I have to ask.

I cannot get my wipers to permanent operation. I push the tip of the switch toards steering column and release it - the wiper make one cycle and stop. I am not sure if I have an issue with the switch or relay. Can you tell me how the switch should work:

1. You push the tip, it does a "click" and stays pushed or does a "click" it goes back and wipers go on. Then you push it again, does a "click" again and wipers turn off?

or

2. You push the tip, wipers go on, the tip goes back without any click. Then you push it again and wipers turn off?

Which one is the correct way? Needless to say mine does not do any click. It is a new piece from MB. I installed it some time ago and I do not remember if I checked it for correct operation or just briefly. I avoid driving in the rain, so I did not have a chance to check it in action.

Another thought I just had: perhaps the switch and relay have changed at some stage lete in the production. I do not mean the change that is desrcribed in the Tech Manual (230 vs. 280SL), but a similar one like with switches - when you now order a switch, say for rear window heater, you get a switch that sends an impulse, not a typical on/off switch. Maybe if I ordered a switch from Mercedes, it is also an impulse switch, requitring a different relay? But that is maybe too far going...

A week ago I was cought in an extremely heavy rain. Water just started pouring from the sky that was clear a minute before. I had my soft top up just because I was too lazy to fold it before departure. all was fine going through that rain except I could not get my wipers to operate permanently.

But one thing I have to say with content: I had absolutely no leaks inside - neither from the soft top nor from the floor! Very happy about it!

[Benz Dr.]

It should click on and then another click to turn it off. I guess is that you have something wrong with your wiper motor. As far as I know there is only one relay used and if your wipers are working I'd say it's working too.

[Pawel66]

Dan, thank you!

My switch does not do the click - it looks it just sends the impulse, not switches anything on permanently... I will need to check that.

I took a close look at the relay in the meantime. I do not think I have the wiper relay, just regular 5pin relay. On the outside it looks similar to the 4pin relays we have for warm start. It is not the SWF relay with a bracket for mounting on top. Inside it is just a regular relay with two contacts in the secondary circuit, one of which does not end with a pin.

I guess I need to start with a proper relay.

Anybody any idea for sourcing a wiper relay?

Mercedes - NLA
SLS - NA
Authentic classic -do not have it
Bud's Benz - do not have it
Ebay - no trace
NIemoeller - I asked, waiting for reply

Does not look too encouraging 

[Paul & Dolly]

Hi Pawel,

Have a look at Wolfgang,s site ,Google  w113.eu, he in Germany and  is a member here I think also.
He has many interesting ideas for our Pagodas, including a replacement solid state wiper relay.I bought one from him a short time ago.

Good luck
Paul

[Pawel66]

Paul, hi!

Thank you for the tip - will do!

Pawel

Just tried - they only have conversion kits. I will keep on trying before I go for conversion...

Thanks again!

[rgafitanu@gmail.com]

Yes, you don't have the correct relay. I opened one and it is far more complicated than the regular relay. It receives the impulse from the switch and and it flips from on to off and from off to on. I got one from eBay but it was expensive. Stopping in the rest position is achieved by the motor unit so if it stops when horizontal the motor is good.

[awolff280sl]

you may want to try this:

http://www.smart-screen.co.uk/

Very nice upgrade, once you get the hang of it. Especially nice is the wash-wipe feature.

[Pawel66]

Thank you all for tips!

Wolfgang explained to me his conversions: very nice work of fitting electronics to th eoriginal relay housing. I had a meeting at work and when I got to the e-mail to order one, Wolfgang wrote someone from Sweden has just purchased th elast piece  .

I will check on the other link.

[Tomnistuff]

Have a look at Wolfgang,s site ,Google  w113.eu, he in Germany and  is a member here I think also.
He has many interesting ideas for our Pagodas, including a replacement solid state wiper relay.I bought one from him a short time ago.
Good luck
Paul

Hello Paul,
Thanks for posting Wolfgang's site.

Have you installed his solid state wiper relay?  If so how do you like it?

Some time ago I had a wiper relay failure (it's really a latching switch).  I was able to repair it myself, but don't have confidence that it will work long.
I designed a "three-relay latching switch" that should do the same job but I haven't made it yet, although I have the schematic and all the parts.  Like Wolfgang's, it's bigger than the original and requires a box and a pig-tail with the pin-connector on the end.

When you install and test yours, please report your results here.  A wiper "latching switch" that doesn't depend on the pivots and cams and springs and rocker switches (oh my!) of the Bosch "relay" would be a blessing, although I can't really complain about such a complicated electro-mechanical device that has lasted 50 years.  I just wish someone still made them.

Tom Kizer
Levis, Quebec, Canada

[Tomnistuff]

I think I may have misunderstood Wolfgang's site.  I don't speak or read German.  Is his solid state wiper relay the one called, "Wisch - Waschrelais"?

Tom Kizer

[Paul & Dolly]

Tom,

The Relay is the Programmierbaner Intervall schalter Scheibenwischer Relais, but if you use Google Translate on his site I thinks it says Programmable Interval Switch for Windscreen wiper Relay.

My original relay was starting to play up a bit, so that is why I replaced it, and I was very pleased to find Wolfgang`s site.

I installed it,back in  March,  and it functions perfectly, I am really pleased with it, and Wolfgang was really helpful.

I had initially a slight problem in that the connector block pins 56 & 56b (going to the Relay) on my car were the wrong way around, after some corresspondance with Wolfgang, we established that there should be a + from the fusebox on 56b, when the ignition is on.This was not a problem with the old Mechanical Relay, but with the solid state a + is required on 56b.  I swopped the pins over in the block, and all was good.

Keep well
Paul

[Pawel66]

I bought a unit from Wolfgang as per Paul's advise. It is an upgraded programmable unit. Looks like SWF when installed. I will install it over the weekend and see how it works. Wolfgang normally upgrades units that customers send to him, but I did not have one to send, so I bought a part he had on stock. The only difference in the way it looks vs. original is the bottom plate where the pins are - for me it is not important - if I spot working original, I will replace or keep it in case a day comes I will want to replace it.

[Pawel66]

Ok, installed the relay from Wolfgang. Works great. I now have wipers with a rain sensor in Pagoda. I am the rain sensor  . I switch on intermittent operation with the frequency depending on when I think it is enough rain drops on the windshield.

[Naj ✝︎]

I had initially a slight problem in that the connector block pins 56 & 56b (going to the Relay) on my car were the wrong way around, after some corresspondance with Wolfgang, we established that there should be a + from the fusebox on 56b, when the ignition is on.This was not a problem with the old Mechanical Relay, but with the solid state a + is required on 56b.  I swopped the pins over in the block, and all was good.

Keep well
Paul

This seems to be a common error.

The wiring on my 280 SL was exactly the same. The wire had to be moved to another slot for the intermittent switch to work.

naj

[JamesL]

Wonder if it's an RHD issue as mine is the same and conversations with Paul suggest that 56b might be my problem: washers work, wipers don't with Wolfgang's relay

Hopefully an easy swap?

[Pawel66]

I have no idea what I had because all the wires just popped out of my plug when I opened the cover  . I had to redo the placements in the plug.

I am enclosing wiring that Wolfgang gave me for the relay he sent to me.

[Paul & Dolly]

It may well be a RHD issue as James suggests, but the fix is simple enough, just swop the 56 and 56b pins over in the connector block under the relay.
(Take a photo before you start, as all 4 pins are likely to try to escape!)

We have just returned from the M-B Irish tour,and Wolfgang's relay was great in some of the inclement weather.
989 trouble free miles at 19.8 mpg

Keep well

Paul