Windscreen wiper motor assembly advice please

[Stenno]

Hi guys, before I complain to an ebayer, need to check my theory! I bought a used windscreen wiper assembly off of ebay, like the one pictured below, however on arrival, and like the one I removed, it doesn't even move by hand?

Now am I wrong or should this be possible? Or is the motor really that powerful?

http://i.ebayimg.com/t/VAUXHALL-CORSA-D-FRONT-WINDSCREEN-WIPER-LINKAGE-MOTOR-NEW-/00/s/MTIwMFgxNjAw/$(KGrHqJHJDoE8fkjbuKIBPH+nPbsBw~~60_12.JPG

Cheers for any answers.
Ian

[tigersaw]

yes, most likely high gearing.
I cant turn my leccy screwdriver tip round by hand, same reason

[daveyrach]

From memory from my time working at Honda they don't. Maybe your old one does due to a fault.

[Sid Squid]

You can't turn the them by hand usually - there's a lot of reduction between the motor pinion and the quadrant.

If possible take the cover off the motor pinion and turn it by hand.

[Spank86]

If you find a nearby car (not your own) and try to use the wiper blade to turn the motor you'll find that the wiper blade just bends and breaks, the motor wont turn, and that you're now wanted for vandalism.

[Stenno]

Cheers guys. The mounting was so corroded it fell off during transit anyway. Just wondered if there were any more issues to add to my woes haha

[sputnik]

The mounting was so corroded it fell off during transit anyway. Just wondered if there were any more issues to add to my woes haha

Well how are you going to fix it to your helmet then!:rolleyes:

[Stenno]

Well how are you going to fix it to your helmet then!:rolleyes:

Boom boom ;)

[SIII]

http://auto.howstuffworks.com/wiper1.htm

Use of worm gear will mean you will be unable to turn the motor. Unlike with ordinary gear trains, the direction of transmission (input shaft vs output shaft) is not reversible when using large reduction ratios, due to the greater friction involved between the worm and worm-wheel, when usually a single start (one spiral) worm is used. This can be an advantage when it is desired to eliminate any possibility of the output driving the input.

Hope this helps to explain.

[monkey]

We need at least a picture of the rotter.

[Sid Squid]

http://auto.howstuffworks.com/wiper1.htm

Use of worm gear will mean you will be unable to turn the motor. Unlike with ordinary gear trains, the direction of transmission (input shaft vs output shaft) is not reversible when using large reduction ratios, due to the greater friction involved between the worm and worm-wheel, when usually a single start (one spiral) worm is used. This can be an advantage when it is desired to eliminate any possibility of the output driving the input.

Hope this helps to explain.
In part, yes. The deciding factor is whether the worm gear's teeth are aligned above or below 45 degrees to the axis of the shaft, if at a suitable angle the worm can be driven by the gear, inefficiently it's true, but it can be.

[Stenno]

Turns out you can turn it by hand just about, or it's far easier with a socket wrench. Unfortunately mine was definitely seized and what with the replacement being broken, I've requested they send out a new one so we'll see what comes of it. I'm going to take my one to work and try pressing the shafts out to clean/grease however I think the housing will break first.

Hopefully the replacement won't be so corroded, but I doubt it!