Wipers making jerky movement on random wipes

Brussels Sprout

Last week I stupidly turned on my windscreen wipers in the morning when there was frost on my windscreen. I was hoping that the wipers would knock the frost off but the wipers were frozen to the glass and although I could hear the motor operating they didn't budge.

I defrosted the windscreen and the wipers seemed to be operating normally. However, what happens now is that randomly the blades make a big jerky movement when they are half way up the glass accompanied by a horrible screetching sound. Sometimes this doesn't happen at all, whereas other times it happens on several consecutive wipes. The worst is that it's fairly random which means that I can't get used to it.

The blades still carry out their function but it's really annoying when they jump and I'm worried that there might be some underlying problem with either the motor, the linkage or the wipers themselves.

Any idea what's the most likely problem here and what is the best solution?

Edit: car is a 04 Focus for what it's worth

Curran

Need new wipers blades/rubber...you've created lots of tiny peaks and hollows on the contact area, when they rubbed over the frost!

CJhaughey

You have damaged the wiper linkage. It will need to be checked and fixed/replaced.

Brussels Sprout

I hope you're right Curran and you're not CJ (purely from a cost point of view)

Brussels Sprout

I just checked them again, this time from the outside and I realised what the problem is. Sometimes the left hand end of the wiper on the right hand side of the car tucks underneath the right hand end of the wiper blade on the left hand side (when both are in the down position). When this happens one blade gets caught behind the other at the start of the upward stroke and when it is released it jumps upwards to reach the position where it should have been.

So, I presume the solution is to alter the angles that the blades are currently at. They must have shifted when I applied to the power to them when they were frozen on the screen.

colm_mcm

With the wipers off the screen, check for play in the wiper arms.

Brussels Sprout

colm_mcm wrote: »

With the wipers off the screen, check for play in the wiper arms.

I'm not sure what that means. I removed them both last night and let the motor turn the spindles a few times before re-attaching them both and now it all seems to be fine again.

Curran

If I were you, Id change the wipers first, and see how you get on - cheapest thing to rule out, and sure if its not the exact problem, you have a spare set of blades!

biko

With the wipers in an upright position away from screen, check if they still jerk. As posted before, it's likely you messed up the linkage but it could be an easy fix. You won't know until you've had a look.

Brussels Sprout

The problem is solved. The linkage, thankfully, is fine. The wipers were misaligned after I turned them on when they were frozen to the screen. This resulted in them hitting each other and causing the jumping. I unscrewed the base nuts and removed both wipers completely from the screen. I turned the motor once in a complete revolution and then replaced the wipers making sure to set them at the correct angles before tightening the nuts back on again. Now they're working perfectly. Thanks for the input.