Firstly I'm sorry if this has already been posted somewhere, or if I'm posting this to the wrong section - I have researched and could only find old threads where people have encountered this problem, but I couldn't find this fix offered, or at least not with a detailed walkthough.
Recently my rear wiper started making only a partial a sweep, stopping at a random position, and only continuing with another press of the wiper stalk - it wouldn't just do one full sweep and return like normal. I've seen people recommend replacing the relay or even the motor, however in my experience neither was necessary. The problem seems to be the electric contacts inside the wiper motor that tell it when to 'park' the wiper blade gradually gunk up with grease and stop making a reliable connection, so the motor prematurely thinks it should stop rotating. Disassembling the motor and cleaning these connections fixed the problem in my case.
Safety first: Ed China says when working with electrics to first disconnect the battery - I don't know if it's strictly necessary for this job, but I figured it wouldn't do any harm.
1: Remove rear wiper blade. This can be a pig, as mine had corroded on to the wiper motor drive spindle. A puller really helps, as does some WD40, but in the end I had to hacksaw some of the plastic away from the back of my wiper arm so the puller could grip properly. Be careful not to damage the wiper motor spindle if you try this.
2: Remove wiper motor. Undo 4 torx bolts from the plastic trim panel inside the tailgate, then gradually peel away the panel, popping off the plastic trim fixings - they shouldn't break if you're careful. Unplug the power feed plug to the wiper motor, and undo the three bolts attaching it to the tailgate.
3: Open up wiper motor. My rear wiper motor is a Valeo OEM unit - I assume this is standard for most/all Corsa C models. Remove the six or seven small torx bolts attaching the black plastic cover plate to the metal housing. I couldn't manage to remove the plastic piece completely as it wouldn't slide off the wiper drive shaft, but if you remove the small bushing at the end of the drive shaft and the washer beneath it, you can slide the plastic part far enough up the shaft to be able to rotate it round and reveal the gears and other internal parts inside the metal housing.
4: Under the large gear wheel that's rotated by the worm gear attached to the motor itself should be three metal fingers. Bend these up a bit so they make better contact with the metal disc on the underside of the large gear wheel that lives on top of them. My motor also had masses of grease that had accumulated all around these metal fingers, so try removing this as well, and give the area a clean. Problem - hopefully – solved, and for free.
I'm sorry I don't have any photos to accompany this - I just winged it at the time as I didn't set out to make a guide.
Recently my rear wiper started making only a partial a sweep, stopping at a random position, and only continuing with another press of the wiper stalk - it wouldn't just do one full sweep and return like normal. I've seen people recommend replacing the relay or even the motor, however in my experience neither was necessary. The problem seems to be the electric contacts inside the wiper motor that tell it when to 'park' the wiper blade gradually gunk up with grease and stop making a reliable connection, so the motor prematurely thinks it should stop rotating. Disassembling the motor and cleaning these connections fixed the problem in my case.
Safety first: Ed China says when working with electrics to first disconnect the battery - I don't know if it's strictly necessary for this job, but I figured it wouldn't do any harm.
1: Remove rear wiper blade. This can be a pig, as mine had corroded on to the wiper motor drive spindle. A puller really helps, as does some WD40, but in the end I had to hacksaw some of the plastic away from the back of my wiper arm so the puller could grip properly. Be careful not to damage the wiper motor spindle if you try this.
2: Remove wiper motor. Undo 4 torx bolts from the plastic trim panel inside the tailgate, then gradually peel away the panel, popping off the plastic trim fixings - they shouldn't break if you're careful. Unplug the power feed plug to the wiper motor, and undo the three bolts attaching it to the tailgate.
3: Open up wiper motor. My rear wiper motor is a Valeo OEM unit - I assume this is standard for most/all Corsa C models. Remove the six or seven small torx bolts attaching the black plastic cover plate to the metal housing. I couldn't manage to remove the plastic piece completely as it wouldn't slide off the wiper drive shaft, but if you remove the small bushing at the end of the drive shaft and the washer beneath it, you can slide the plastic part far enough up the shaft to be able to rotate it round and reveal the gears and other internal parts inside the metal housing.
4: Under the large gear wheel that's rotated by the worm gear attached to the motor itself should be three metal fingers. Bend these up a bit so they make better contact with the metal disc on the underside of the large gear wheel that lives on top of them. My motor also had masses of grease that had accumulated all around these metal fingers, so try removing this as well, and give the area a clean. Problem - hopefully – solved, and for free.
I'm sorry I don't have any photos to accompany this - I just winged it at the time as I didn't set out to make a guide.
its just easier to tell some people to swap the motor over :shrug:
