Problem with wiper windscreen

[RobertK]

I have since yesterday a problem with my windscreen wiper.
Driving during the rain yesterday, it runs fine in the beginning. At a certain moment it runs more slowly and sticks in the middle of the screen.
When I turned it off, and put it on again it goes normal until a minute or so. It sticks on the left side (driverside) of the screen with noise and it does not wipe anymore.
After parking the car, I investigated the wiper from outside and I saw that it was too long to move free. The wiper does not move when I turned it on.

Today I have lubricated the alu shaft, but it does not help. Testing again it sticks again on the left side.

Does anyone experienced this issue in the past ?
Is the wiper mechanism defect ?
How can I cure this issue ?

 

[TimL]

I believe @JC220 had a really good how to on servicing the wiper mechanism

HOW- TO: Complete windshield wiper mechanism lubrication + upgrade | "HOW-TO" Tutorial Articles

This DIY will cover my rebuilding & upgrading of the wiper in my 1992 500E. The removal of the wiper itself is not included as this information is widely available – I prefer to concentrate on the wiper mechanism itself for purposes of this DIY - which involves full disassembly of the wiper...

www.500eboard.co

 

[gerryvz]

Likely that you will indeed need to take apart for lubrication and potential replacement of the gears, if broken or damaged. I believe I remember that @Melville had a thread or some info on gear replacement, as well?

 

[gsxr]

Quick check is to squirt lube on the shaft which moves in/out... this MAY help or cure the problem.

If no change, you'll need to open it up, which is difficult on models built prior to late 1993.

 

[RobertK]

I have already lubricated the shaft which moves in/out but it behaves the same. It sticks on the left side when I put it on immediately.
I have to open it up indeed but I am not happy with the effort it will take potentially to fix it.

An other solution should be buying a later (better) unit with the plastic cap. I know one from a E500 of 1993 or later.
Are these unit exchangable from the newer to the older types ?

As mentioned earlier I have an 1992 (July) Japan import 500E

 

[gsxr]

An other solution should be buying a later (better) unit with the plastic cap. I know one from a E500 of 1993 or later. Are these unit exchangable from the newer to the older types ?

As mentioned earlier I have an 1992 (July) Japan import 500E

The later type with plastic cap have a completely different seal/weatherstrip. I think mechanically they will interchange, but swapping the seal may require disassembly of the gear mechanism, which may not be any savings in the long run.

 

[gerryvz]

I would just buy a used one in working condition and replace it, if you don't want to tear down and repair the one you have.

 

[RobertK]

Yes, that should be for me now the best idea.
Thanks !

 

[Melville]

Likely that you will indeed need to take apart for lubrication and potential replacement of the gears, if broken or damaged. I believe I remember that @Melville had a thread or some info on gear replacement, as well?

Gerry is right. That sounds like my situation. Highly likely one of the gears is broken. Here's the thread:

Windshield wiper not retracting / extending properly | Troubleshooting and Diagnostics

Now that the nice weather is approaching, I need to address an issue on my 1992 500E. The windshield wiper mechanism is not working properly. The blade does not retract and extend as it should. The centrifugal force pushes it out so that it hits the A-pillar at the base of the windshield...

www.500eboard.co

 

[RobertK]

Yes thanks Melville I have red your thread.
Lack on lubrication should be the cause of this I think. I have bought a used one which I have tested this afternoon. It works well.
Only the rubber seal is different (mine is bigger) so I have to swap it.

 

[jftu105]

Well, as I discussed in my other threads, I had to replace the motor twice for my E320, 1994, first time with a wrong 1992 motor which has no Back EMF killing diodes, and then a new VEMO unit. The chance is that the motor is weak with the brush wearing out or the coil shorting. You can measure the resistance of the motor coil which should be about 10 ohm. If it is down to 2-3 ohm, the insulation of the coil wire is failing.

jftu105

 

[RobertK]

Allright, I will do that. Which pins should I have to measure ?
In my situation the replacement motor is an older type then the one in my car. Then it is not a problem I suppose ?
(no diodes etc, also in the 1992 models)

By the way: the gearing of my own wiper mechanism has been destroyed, as expected.

 

[jftu105]

See the discussion in the link below. Get a new motor with a diode. I think there are 4-5 pins. Only two of them are the direct connections to the motor coil. Other pins are related to the limit switches. Therefore, just measure the impedance across any two pins. The one with a reading in a few ohms will the coil impedance. I think that they are the first two pins.

jftu105

Wiper motor, a critical but often neglected part | Troubleshooting and Diagnostics

It has been raining lately and when I needed it the most, the windshield wiper became slow and lethargic. Then I smelled some burned plastic smell. Alarmed, I shut off the windshield wiper but it was raining, luckily light. I was able to drive without using it. Arrived home and checked...

www.500eboard.co

 

[RobertK]

The replacement motor shows 10,4 Ohm. My old motor has a higher resistence: 30-32 Ohm.

 

[dionphaneuf]

What's the cutover for the late style wiper mechanism? I thought it was exclusively 94-95 models, but it sounds like it made it to some 93s...this poor guy made it to my local junk yard and is a 93 with a 9-1992 approximate build date, so maybe too 'late' of a 93 for what I need in my 92?

Mercedes VIN Decoder | Decode Your Mercedes-Benz VIN

Datacard for 1993 Mercedes-Benz 420 E (124.034) - WDBEA34E6PB854076

www.lastvin.com

 

[gsxr]

The 1993 400E you listed is an early build 1993 USA model year, and should have the older wiper with metal housing, and separate left/right detachable trims at the base of the windshield. If so, it should match what you need for your 1992 500E.

Late-build, pre-facelift cars had a hybrid wiper setup that used the older all-metal housing, with the late one-piece rubber weatherstrip. I owned a 1993 300D, chassis B991xxx, production date May 1993 which had this wiper. My 1994 E500 (C003xxx) produced early July 1993 had the same hybrid setup. I don't know the cutover point but it would have been early 1993 calendar year, or mid/late 1993 USA model year.

Later facelift cars had the late weatherstrip and also the plastic housing which pops off, for easy lubrication of the gearing. I don't know the cutover but by Jan-1994 (C102xxx) MB was using this newest version. The change was somewhere between July and December 1993.