Windcreen Wiper Motion W124

[John Turner]

The wiper on my 1995 W124 does not always 'park' in the correct position - and this is especially annoying on intermittent. Indeed it parks in virtually any position, depending where in the cycle I turn it off. The wiper blade is new and my windscreen is clean and 'rain-away' treated. I have regreased the pistion and mechanism under the turtle shell, and used electrical contact cleaner on the relay. The windscreen wiper motor is vigorous. Might I have a problem with the control stalk in the car? Any ideas gratefully received.

 

[tom7035]

I would suspect a faulty relay, though I'm no electrical guru.

 

[television]

The parking switch is inside the motor, the set of contacts in the motor do the parking. the stalk closes the relay that supplies the +12v over the contacts,when the power is removed, the parking switch opens,and the motor stops. It will not be the stalk, if the motor just stops when you turn it off, it will be the parking contacts.

Malcolm

 

[John Turner]

Thanks Malcom. When I switch the wiper off, the blade stops a second or two (or less!) later, and it is very difficult to switch off such that the wiper parks to the right. The parking contacts sound plausible. Are these easy to access and clean?
Thanks
John

 

[television]

This is not an easy job to get the motor out, I think that one of the contacts may have broken off. when the wiper switch is on this start the motor, when off, the prking contacts stay closed, when the cam wheel gets to the park posistion it opens the contacts, and its parked. the wiper switch goes through a relay, I do not know if the parking power comes from this relay.
With the ignition on, and the wipers left off in the middle of the screen,tapping the relay would show up any faults there.
If you do take it out, the gears must not be disturbed, otherwise the parking possition will be lost.

Malcolm

 

[John Turner]

Many thanks. I will check relay first just in case.

 

[macca2210]

I've had the same symptoms with a '94 E220 W124.

The wiper is OK on full or double speed, but on intermittent, it stops at a random place and is hard to get back in the home position.

Checked that the relay (N10) is activating. You can hear the intermittent relay switch on for about 1-2 sec, and the wiper moves while the relay is active. If I push on the relay, the wiper works properly.

Found that the big pin on the end of the relay, pin 31A I think it was was the likely problem. Could be that it was a dry joint, so re-soldered the circuit board where the pin connects, and where the normally closed relay pole connects to the circuit board. Seems to be working reliably now.

Greased the slider mechanism (under the large black cover) with PTFE grease and all is back together.