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MG Midget and Sprite Technical - Help with self-park wipers

Hi All,

A while ago I rewired the wipers correctly (I think) having undone a great deal of bodgery by a previous owner. I now have two speeds and a reliable self-park.

But, today I was mocking up my windscreen template to get the best position (for my custom windscreen surround) and, to check the position and angle was still right for the wipers. I fitted the wipers and found that they park on the wrong side and so the parking mechanism is effectively 180 degrees out. Now I have not had the wiper motor assembly completely to pieces but I did (ages ago) remove and replace the cylindrical motor cover that also holds the magnets. But even if that was put on the wrong way around it would only change the direction of the motor and that doesn't matter as far as I can tell.

Can anyone tell me where I've gone wrong?

Nick

Nick Nakorn

Did you remove the wiper boxes? If so, you have re-mounted them 180 degrees out from where they were before. Just turn them over 180 degrees so the rack is running the other side (i.e. below if currently above and vice versa).

Otherwise just remove the arms/blades, let the wiper motor run and park, and refit the arms / blades in the correct parked position.
dominic clancy

He's right, the only way that the motor can park 180 "out" is if the self park "ramp" on the bottom of the wiper drive gear gets swopped to the other position.



Must be in assembled differently
SR Smith 1

Or the wheelboxes have been out and re-assembled on the wrong side of the rack cable.
Guy Weller

I think the most likely is the wheel boxes. I need to get the dash out again anyway at some point so I'll check it out. Great advice; thanks all :-)!
Nick Nakorn

Well, it's all a mystery. I've had the dashboard out again, as part of my A-pillar work, and decided to solve the wiper problem before I forgot to do it. I dismantled the wheel boxes (with the cable running under the wheel) and cable assembly and tried reassembly with the cable over the wheel. The result was that the outer tube was now about 1" too short to reach the motor and the tubes were all at the wrong angles. I definitely had them assembled correctly before.

So I now tried to remember if, when the old wiring (made up of all sorts of scraps but mainly of domestic earth wires)was still connected, I actually tried the self-park. Frankly, I can't now remember. So it might have been that the self-park was disconnected when I bought the car. So, what I've now done is to remove the spindle and crank mechanism, disengage the nylon gear-wheel, with the parking cam on its underside, from it's tabs and move the gear-wheel 180 degrees relative to the crank-wheel.

The spindle for the crank/gear assemble is only secured to the casing by a circlip so it was reasonably simple. I wonder if the wiper motor assembly was originally for another car and I also wonder of the park circuit works differently for positive and negative earth cars.

Anyway. At least I now know that it should all work as it should when it's wired up again. So if anyone wants to know how to fix the problem I had, the answer is that the easy way is to turn the crank wheel 180 degrees relative to the gear-wheel.

Cheers all!
Nick Nakorn

Positive earth cars had a different - square-bodied - motor.
Dave O'Neill 2

Hi Nick,

The 14W wiper motor was fitted to nearly the whole of the BL range either in single or two speed form from about '69 on and right up to the present day on Land-Rovers.


The only differences were the side it originally parked and the angle of the sweep, which is stamped on the drive gear.


The original side of parking was stamped on the cover.


Indeed new motors were normally supplied less the drive gear, which had to be swapped over from the old unit.


As Dave says, older cars used a DR3 or 3A square bodied motor. and the parking worked on a different principle.
SR Smith 1

Nick,
by swapping out the cog and arm (I forget the proper part name for the part, David might say) you can get a wider sweep from the wipers (IIRC correctly standard is 105 degrees?)
Nigel Atkins

Thanks for all the info chaps. I think the sweep will probably be OK though I'll have to wait till I'm roadworthy to find out; of course extra sweep is always good but I'm more interested at the moment in the shape and length of the wiper arms as my new windscreen will be in a slightly different position from stock. The good thing is though that at least now the wipers will park in the right place and not head towards the bonnet when they start! Thanks again all.
Nick Nakorn

Nick,
don't bother using modern made Tex wiper arms or blades they're useless - see Archive
Nigel Atkins

This thread was discussed between 07/08/2014 and 26/08/2014

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