Wiper system on W210

[woodturner-fran]

Ok, its a 1996 W210.035 non- rain sensor wiper.

The wiper works AOK, you're driving along on a rainy day, and after a while maybe an hour or so, the wiper starts to slow down. Now it isn't jerky, doesn't stop anywhere, it just starts to get really slow. It still completes its cycle and stops in the right spot. You panic and wonder am I going to be able to get home.... Luckily the day dries up and a few hours later you arrive home.

The next morning you go out and the wiper is working AOK.

I've greased the piston shaft (which was free and not sticky).

Once I turned on the wipers and the SRS light came on for a second or 2, I only noticed because the radio turned itself off and then back on.

Has anyone any ideas? Am I looking at a mechanical or electrical problem. Is it a voltage issue? perhaps the battery is getting old?

what do you think?

Fran

 

[woodturner-fran]

OK, a pet hate of mine is not following up on posts to let people know how a problem is solved... see the thread in the general area at the moment...


So, back on topic... I took out the wiper motor assembly tonight and took it apart (after the wiper almost stopping today in the wicked rain we had here). It was easy enough to do. I checked all the linkages and they seemed free enough, couldn't see any thing wrong there so I actually took out the assembly - so I kinda ruled out a meachanical issue - onwards to electrical! I opened the cap off the motor-to-linkage part - the bit with the nylon gear wheel. I was fully expecting to see the gear all chewed up... but good news it was perfect. I then noticed that there were 2 electrical "points" (like the old points on cars when they had them) that rubbed on a brass connector on the nylon wheel. I guess that this has something to do with power flow when the wiper is jammed or the like. So I sprayed on a bit of switch cleaner and rubbed down the brass plate and contacts with a bit of 1500 grit abrasive, re greased up the nylon wheel with some copper grease and reassembled the whole thing.

I bent out the 2 contact points so that they would make good contact, put the whole lot back together.

The weather is to be crap here for the next few days so if this job was successful then I'll let you all know,

Fran

 

[woodturner-fran]

OK so that didn't work...

coming into work this morning and the wiper slowed down with every wipe, then almost stopped for an instant then almost immediately came right back up to speed. When it stopped for a second, the radio went off and then back on again.

Wiper was AOK then for the rest of the journey.

Leads me to think of more electrical issues specifically in the control or supply voltage

Any ideas anyone?
Fran

 

[woodturner-fran]

Any further takers on this one? Anyone know where the wiper relays are on a W210 and what they look like. Could a faulty relay cause these problems?

Fran

 

[joe bloggs]

I would go for the motor, is the fault on both speeds? is the motor really hot when running slow? with the arm pulled up, and the wiper stopped but not parked (stopped via ignition) is it easy to move it across the screen?

You could try stripping the motor and cleaning up the brushes, armiture etc, and lubing the bushes.

Unlikely to be the switch, possibly the control relay, have a look at the fuse, could be poor connection which would get worse when under load as it heats up. Have a fiddle with the switch / relay / wiring when it slows down, does it change speed?

Still think its the motor though.
Happy hunting.
Relay is at rear of fusebox in earlier?? 210's, 6 screws holding fusebox relaybox cover on, later cars...I will need to nip into the workshop and look at one.

 

[simon morgan]

wiper problem

I think this is electrical. I have a 1992 300SL which I have recently acquired.

There are occasions, when I start the car, that nothing on the wiper stick works-on my car that includes indicators! I have also noticed that the cigar lighter also does not work. After an indeterminate distance the SRS light shines for a second or so and everything is fixed! I wonder whether it is linked to the steering column which is directly linked to the SRS bag.

I took it in for a fix to an MB specialist who replaced the voltage regulator. It made no difference but cost me £250. I now live with it.

Does this help?

 

[woodturner-fran]

Thanks for the suggestions.

Its easy enough to move the wiper across the screen as you suggest Joebloggs - I noticed this when taking the blade off. I didn't try to see was the motor getting hot - I'll be trying that at the first opportunity. I took out and checked teh fusews and sent them back in with some switch cleaner. They seemed AOK. I don't think its this beacuse it gets slower after a good time (I've noticed this on intermittent and 1st speed) then stops and all of sudden resumes at proper speed and continues to work. Thats why I wondered was it mechanical and the "stop" resetting some kind of relay

will post more as I investigate further

Fran

 

[woodturner-fran]

Well the wiper finally gave up the ghost today. It had been getting worse over teh past while, slowing to stop on every journey, and then going again as if nothing had happened.

Today it didn't get going again. Continuous clicking from the control relay module (front LHS back of wheel arch). Took out the module and opened it but I couldn't see anything wrong. I think it has to be this... so I'm off to hunt for a spurious/secondhand module. I think this relay controls loads of stuff - SAM? relay?

The photo (poor I know) shows the label on the box. Does anyone know if this is a common part for a few different mercs? (I know the PN starts with 210 so maybe not).

WIll post when I know more.

Fran

 

[nellouk]

How did you remove that module?

I have experienced the same problem and the relay in that module is clicking madly.
I cannot however remove the module from the large wiring box.