Windshield wipers not moving

[MNtraveler]

Given the cold weather, they might have gotten stuck for a moment when first turning them on when they did not move. However, the windshield is now clear and the wipers still do not move. After turning them on, you can see the motor cycle on them to move the base just slightly then shut off. Turn them off then on again and the same thing happens. The arms are free and clear and there is no apparent icing or anything else under the hood - it looks quite normal under there. Any suggestions that might save me a trip to the local MB service station? Thanks!

[Still Kickin]

First; not quite sure what you mean by the base moves. Do you mean the spline shaft that the wiper arms connect to. Second; since you say you get some movement when you engage the switch, that seems to rule out a fuse blown.

Try taking the load off the wiper arms prior to switching on, by placing the arms in the perpendicular position , then switch them on. Search Sprinter - Sprinter-Forum that might point you in direction.

[MNtraveler]

Originally Posted by Still Kickin

First; not quite sure what you mean by the base moves. Do you mean the spline shaft that the wiper arms connect to. Second; since you say you get some movement when you engage the switch, that seems to rule out a fuse blown.



Try taking the load off the wiper arms prior to switching on, by placing the arms in the perpendicular position , then switch them on. Search Sprinter - Sprinter-Forum that might point you in direction.

The base the blades are attached to wiggles a little bit but not enough to move the blades, then it stops. Say it moves up 2mm than back 2 mm. It moves a bit for roughly one second before stopping. I'll try your other suggestions in that order. Thanks!


Land of 10,000 Lakes
2016 Forester MBS 2401R

[Still Kickin]

Originally Posted by MNtraveler

The base the blades are attached to wiggles a little bit but not enough to move the blades, then it stops. Say it moves up 2mm than back 2 mm. It moves a bit for roughly one second before stopping. I'll try your other suggestions in that order. Thanks!


Land of 10,000 Lakes
2016 Forester MBS 2401R

Sounds like it's a trip to your MB dealer if you can't find a simple reason why it isn't operating correctly.

[MNtraveler]

Originally Posted by Still Kickin

Sounds like it's a trip to your MB dealer if you can't find a simple reason why it isn't operating correctly.

Ah, now not so fast! Your first idea was a good one. I lifted the arms outward and then engaged the wiper motor. Surprisingly, one arm rotated one way and back but the other one didn't move. Stepping out and looking closer, the arm that didn't move had a very loose nut that is supposed to hold the arm to the drive shaft. I tightened this and it then moved in the air but would not move more than a bit when I put the arms down on the windshield. Curious.

Looking at it further, it gives the appearance that the motors are trying to move the arms down, not up, but shuts off because it can't move them down past the docking point. I have a hunch. I think both arms are now attached in a way that the motor thinks they are at the top of the cycle not the bottom where they actually are. I'm guessing this happened during the initial cycle when they were stuck - the motor and drive shafts moved but not the arms so there was slippage (probably intentional slippage design to prevent motor damage). I'm going to remove both nuts and put the arms up at the top of the cycle, re-tighten the nuts and see what happens. Now the unit is in my driveway so I can fiddle with it more tomorrow when it warms up (to a toasty 34!).

The great news thanks to your first step was to find out that the motors are not frozen! 👍 Thanks again for your suggestions.


Land of 10,000 Lakes
2016 Forester MBS 2401R

[MNtraveler]

Update: The motor works fine. The rods that attach to the arms turn back and forth with the arms off. With the arms on, the arms do not move. There is something wrong in the connection between the rods and the arms. The fittings appear to be shot (worn out). So, it's off to the MB dealer today, which happily said they could see me to at least diagnose what the problem is today.




Land of 10,000 Lakes
2016 Forester MBS 2401R

[3886john]

Half a turn on each nut will fix your problem.

[Still Kickin]

Originally Posted by 3886john

Half a turn on each nut will fix your problem.

We are still talking about wipers here, right!

[Still Kickin]

Originally Posted by MNtraveler

Update: The motor works fine. The rods that attach to the arms turn back and forth with the arms off. With the arms on, the arms do not move. There is something wrong in the connection between the rods and the arms. The fittings appear to be shot (worn out). So, it's off to the MB dealer today, which happily said they could see me to at least diagnose what the problem is today.




Land of 10,000 Lakes
2016 Forester MBS 2401R

Sounds like your splines are rotating inside the wiper arms. You probably need new arms, as that lose fitting you described probably caused some stripping on the arm. Splines are pretty much bulletproof. Or, the linkage got boogered (not a real mechanics term).

[MNtraveler]

I think the arms are stripped. We'll see momentarily.


Land of 10,000 Lakes
2016 Forester MBS 2401R

[MNtraveler]

That was easy! The little nuts look like finger-tighteners but the black cap is cosmetic - under that is a hex nut that the mechanic tightened down (and I mean tight!) and now they work fine.

NO CHARGE!

Which is a good thing because the walk-in diagnosis charge is $149.95!




Land of 10,000 Lakes
2016 Forester MBS 2401R

[MrLucky]

Same problem 6 months ago. Spline connection on motor completely stripped. Extended warranty covered replacement motor repair completely. Whew!!! Good luck. 😎

[MNtraveler]

Originally Posted by 3886john

Half a turn on each nut will fix your problem.

You were correct, give or take a turn. However the black cover threw me off. It won't next time! Thanks.


Land of 10,000 Lakes
2016 Forester MBS 2401R

[MNtraveler]

Screen shot, not a video:



Cap off:




Land of 10,000 Lakes
2016 Forester MBS 2401R