Wipers not working

[iveco]

yes both flash 3 times and alarm is working

 

[iveco]

What year is the R171?

Dec

2006

 

[iveco]

What year is the R171?

Dec

2006

 

[brucemillar]

No, it suggest the car thinks the door or bonett is closed, that assumes the car alarm is in full working order.

Dec

Apologies. My bad. I should pay more attention.

 

[Dec]

yes both flash 3 times and alarm is working

My own W202 and I know a W211 will flash 2 times if bonnet is open, maby things are diffrent with a R171.

If the alarm is triggered it should sound for 30 sconds and flash the hazzards for 3 minutes and then reset itself.

Dec

 

[Dec]

Above is a typical wiper motor gearbox, the Yellow gear, driven by the worm drive, will do one complete turn, clockwise, for every complete cycle of the wiper arms, a cycle moves the wiper arms from park, across the screen and back to park at the bottom of the screen.

If the wiper arms stopped halve way across the screen then the Yellow gear would only have moved a ¼ of the way around, if the arms were then moved back to park position, by hand, then the Yellow gear would have moved counter clockwise which would have dragged the 3 copper switches, 1, 2 & 3 backwards, possible causing damage to 1 or 3.

Just a theory, you will probably have to open up the wiper motor to have a look if you can’t fine any another explanation for the fault.


Dec

 

[zipdip]

Well you had better cancel the MOT,I hope like most people you put your car into the MOT a couple of weeks before it is due,I would get a mobile auto electrician round,from your posts it would seem you cannot check for power getting to the windscreen motor,you also seem to have a problem with interior lights that might have something to do with it,if you do not like that idea then there is a complete wiper and arms for your car on ebay for £48,maybe swap your motor and arms complete and see if that works.

 

[chrisk2010]

I've not had much experience with wipers apart from greasing the w202 once a year and the rear on a golf that had been corroded but would it be possible to bench test the motor ?

Disconnect (unplug) the wiper motor, get a couple of loose bit of wire, find which pin are the live and neg from google and just touch them to the battery again being careful make sure it's live to live and neg to neg. If the motor spring to life i suppose the next stop be the SAM connections or a relay BUT if it doesn't i'd just replace the motor as like Dec has stated by forcing the wipers down you've broken inside.

Personally i'd only open it up if i couldn't get one quickly.

 

[iveco]

I've not had much experience with wipers apart from greasing the w202 once a year and the rear on a golf that had been corroded but would it be possible to bench test the motor ?

Disconnect (unplug) the wiper motor, get a couple of loose bit of wire, find which pin are the live and neg from google and just touch them to the battery again being careful make sure it's live to live and neg to neg. If the motor spring to life i suppose the next stop be the SAM connections or a relay BUT if it doesn't i'd just replace the motor as like Dec has stated by forcing the wipers down you've broken inside.

Personally i'd only open it up if i couldn't get one quickly.

 

[iveco]

Hi guys I have taken the wiper motor off and the motor works fine
Think we might be getting there hopefully .
With the bonnet closed you can here a click which seems to be coming from the SAM but you only here this on position 4 on wiper stick not on 123 .
Obviously with bonnet open it does not click at all which confirms it is sending open/closed messages ok .
Is there a relay relating to wipers ? its awkward when you cant have bonnet open as I would be able to hear /feel the click if relay . Sorry for being such a pain !!!!!

 

[brucemillar]

Is there a relay relating to wipers ?

I am not 100% sure on your model. But the SAM may be the relay ;^( If, in the fuse book it describes the fuse as "electronic" this is usually an indicator (no pun intended) that it is the SAM that is acting as the relay. Others will be along who should know more than me here.

You are not a pain.. These things happen and can be very frustrating indeed.

On my W203 C55 AMG, the front side lights did not work. Both tested as having very low voltage -3vdc at the bulb holder. That turned out to be the front SAM that had failed.

 

[iveco]

Thanks its position 3 not 4 there is no 4 .... the fuse chart says windscreen wipers fuse 33 42 46 washer pump electronic

 

[brucemillar]

Thanks its position 3 not 4 there is no 4 .... the fuse chart says windscreen wipers fuse 33 42 46 washer pump electronic

I would be encouraged by that. Assuming all fuses are tested good? Then it does rather suggest that the motor, motor clutch or, linkage is the failure.

Never having seen this particular set up before!! Pay very close attention to the motor for any plastic pins (snapped) and lying inside the covers. Mercedes do like using plastics that are sometimes designed to fail as sacrificial low cost parts to protect the bigger more expensive part?

 

[iveco]

I would be encouraged by that. Assuming all fuses are tested good? Then it does rather suggest that the motor, motor clutch or, linkage is the failure.

Never having seen this particular set up before!! Pay very close attention to the motor for any plastic pins (snapped) and lying inside the covers. Mercedes do like using plastics that are sometimes designed to fail as sacrificial low cost parts to protect the bigger more expensive part?

 

[Dec]

That’s a front SAM above, see this link for more pictures… https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313.TR0.TRC0.H0.TRS0&_nkw=r171+front+sam&_sacat=0

The wipers have 2 relays, usually Yellow, you can hear and feel them click when the are energised. You could try swapping theme around to see if that makes any difference.

You can fool the car into thinking the bonnet is shut if you close the bonnet lock by pushing down on its mechanism with a screwdriver so as to simulate the “square” bonnet catch hitting the lock.

To release the bonnet lock before you shut the bonnet, just pull the Red bonnet release handle in cabin.


Dec

 

[iveco]

Hi I took the wiper motor and arms off and put power to the motor and it worked fine ... defiantly a click coming from the SAM

 

[iveco]

View attachment 74032

That’s a front SAM above, see this link for more pictures… https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313.TR0.TRC0.H0.TRS0&_nkw=r171+front+sam&_sacat=0

The wipers have 2 relays, usually Yellow, you can hear and feel them click when the are energised. You could try swapping theme around to see if that makes any difference.

You can fool the car into thinking the bonnet is shut if you close the bonnet lock by pushing down on its mechanism with a screwdriver so as to simulate the “square” bonnet catch hitting the lock.

To release the bonnet lock before you shut the bonnet, just pull the Red bonnet release handle in cabin.


Dec

 

[iveco]

Thank you , it is the left yellow relay on your picture that clicks swapped them over but both just click

View attachment 74032

That’s a front SAM above, see this link for more pictures… https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313.TR0.TRC0.H0.TRS0&_nkw=r171+front+sam&_sacat=0

The wipers have 2 relays, usually Yellow, you can hear and feel them click when the are energised. You could try swapping theme around to see if that makes any difference.

You can fool the car into thinking the bonnet is shut if you close the bonnet lock by pushing down on its mechanism with a screwdriver so as to simulate the “square” bonnet catch hitting the lock.

To release the bonnet lock before you shut the bonnet, just pull the Red bonnet release handle in cabin.


Dec

 

[iveco]

Thank you , it is the left yellow one in your picture swapped them over but both just click

 

[Dec]

Did you try opening up the wiper motor gearbox?
Yours wont look exactly like the above but will be similar.

Dec