MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG Midget and Sprite Technical - Wiper Motor Set Up

I have just fitted a new Lucas 14W wiper motor along with new rack etc, is there a way of setting the gear wheel in the correct place without any power going to the motor, obviously I can pull or push the rack to the put that in position relative to the gear wheel.
Martyn Wilks

You can remove the retaining clip from the gear wheel shaft, withdraw gear and shaft and rotate to the desired position.
Dave O'Neill 2

Not sure what you mean by "in the correct place"?


If its working correctly the gear will stop in one of 2 postions depending on where the self park plastic ramp is fitted.


Did you swop the drive gear over from your old motor?



By moving the wiper arms to and fro the rack should be moving to and fro in the tube and inside the motor body.
Steve Smith Midget 1500

Martyn,
it's as Steve's put but if you're trying to line it all up by hand without battery power then (I think) you'll need to have the wiper motor gear cover off with the gear arm (shaft) and plastic park ramp in the correct positions.

Either have a look at the Archives on here or take a photo of how yours is now (with cover off) and put it up here (it'll show arm position at least).

If you take the clip off to adjust be careful as Sod's Law it will fly off and disappear for ever.

I done mine when I had severe man-flu so originally got it wrong and couldn't understand why and now can't remember what looks correct - you'll find my thread at least.

I would also normally direct you to Paul Hunt's excellent site on MGBs but the site appears that it might be infected at the moment according to my Avast anti-virus.

Nigel Atkins

Thanks for the replies, I shall post a picture when I can brave the garage again.

What I have is a new motor etc and a NOS gear wheel I did not have an old 14W just an old early type.

My question is where do I put the gear wheel and shaft in relation to the rack position - I have not powered up the motor as the loom is not fully fitted yet so I don't know where the park position is - is there a way of manually setting up the position etc of all the components.
Martyn Wilks

I recommend you remove the wiper arms before you switch on. Then switch on and off to determine if the park position is correctly set.
Doug Plumb

Martyn,
IF (and that's a very big if normally and even more so on this) I remember correctly the shaft arm of the gears points and is raised fully up with the rack drive - hopefully if this is wrong more knowledgeable people will be able to say.

Check what figure is on your gear, I think it's normally 105 degrees(?), but Guy has previously put that 110(?) gives a better swept area (with overlap?).

Take Doug's advice, I can tell you for certain that if you (like I did) have the park ramp in the wrong position it can make your wipers head for the bonnet so I suggest instead of fitting the wiper arms you test first by fitting a couple of pieces of cardboard with arrows drawn on to shown you where the wiper arms would start, go and stop.
Nigel Atkins

Is this right? It seems complex to me but maybe I am being too simplistic.

I thought that the stop position is controlled by a ramp on the nylon drive wheel in the wiper motor. This ramp is fixed in relation to the wheel and the crank pin which operates the push-pull link to the rack. So the park must therefore always be at one extreme of the rotational movement of the wiper rack, the wheelboxes and their spindles. The only variables are therefore surely which way the motor turns (polarity, and probably fixed) and the positioning of the wiper arms on their respective spindles.

Doesn't one just assemble it all, leaving the wiper arms off. Start and let the motor self park, checking which way they rotate before stopping. This positions the splined shafts at one extreme of their movement, and you then just fit the wiper arms to the splines in the appropriate position on the screen.

The different rotational degree one I use (I thought it was 120, but Nigel may be right at 110 degrees) gives a better swept area, with a slight overlap avoiding the tendency for a missed section in the middle of the screen. This presumably doesn't happen anyway with the USA specced 3 wiper arrangement.

And before Mr Stapleton says it - there is a book with this stuff in it
GuyW

Hi again,



If the car was fitted with the old type DR3 square bodied motot, the wiring is different as that motor had a switched ground from the switch (black/green) and the self park was all done within the motor itself.


The 14w type has a 5 way plug and uses a special type of switch to enable the self park to function.



If you want to power up the motor just dab the light-green/red to power and it'll move.



Good points on leaving off the wiper arms before powering up btw,
Steve Smith Midget 1500

what Guy said; just bung it all together, power and park it, then fit the arms.
David Smith

See the difference in swept area for a 100 [possibly 110] and 130 deg gear


Doug Plumb

Thanks again for the replies, to answer a few questions,the gear is 110° (bought from ebay for £14.00 still in its 1984 BL box), the loom is new (from Autosparks) and has been wired for a Lucas 14W 2 speed motor.

My concern about powering up the car is that I have many terminals that are not yet connected up and with all the will in the world I suspect I will short something out somewhere.

I think I may purchase a Sealey PP1 Auto Probe as this will allow me to power up individual circuits and they are only about £15.00 now on ebay.
Martyn Wilks

So why not just set this job to one side, leave the multiplug disconnected until you have completed the rest of the wiring, and come back to this later?
GuyW

I like to finish one job before starting another plus access is easy at the moment which it won't be once I start to add more things to the car including the dash.
Martyn Wilks

Martyn,
I understand what you want (I think anyway) as I'm not an engineer or mechanic.

I'll see if I can find an image of what you ask for.
Nigel Atkins

Martyn,
I hope photo below helps and is in correct position -
someone please correct me if it's wrong.

But check that the parking ramp is in the correct position before installing in motor as I bought what must have been a multi-fit gear and shaft as the slot-in parking ramp was supplied in the wrong position for my car (and had an extra fitting) and my failure to check this caused me even more confusion than I normally have.

IIRC , I think – someone please correct me – the parking ramp fits under where the post is(???) (screwdriver is pointing to clip on post in photo).

Apologies for me not correctly remembering - 110 is standard, 120 suggested by Guy. (Doug adds 130).

As I put before Paul’s site relates to MGBs but much is relevant to Spridgets too (I hope this link works as I can’t test it at the moment) -

http://www.mgbstuff.org.uk/electricstext2.htm#wipers




Nigel Atkins

Thanks Nigel, whilst working on an oil cooler mount I took the attached picture of how mine looks at the moment - I have made no attempt to position in the photo its just how it all worked out after I had finished wrestling with bending the outer tube to the correct shape.

Yes I know the motor is not in the correct place - I wanted to bring it inboard of the inner wing as my one piece front end might have caught on it


Martyn Wilks

I am sorry to be just a little off subject but does anyone have details of how to convert from the Frogeye/midget single speed wiper wiring to the 2 speed 14w motor wiring?
I have been trying to sort this for a while now but no success. Any help appreciated.
Slowly

Martyn,
comparing the photos I think will give you the answer, to me it looks like your parking ramp is 90 degrees out.
Nigel Atkins

Slowly,
you could have a look in the Archives here or have a look at mgb-stuff site or wait for the likes of Steve Smith to reply.
Nigel Atkins

Hi again,



If the motor stops in that position you sure have something wrong! All the parking ramps I've ever seen on the 14W motors fit in one of 2 places at 180 degrees. Thus making the arm stop in line with the drive ie fully "in" or "out".




In answer to someones question about converting the wiring to suit the newer motor, it is simple enough. You'll need the correct 5 pin multilpug and enough wiring to reach the dash switch. Additionally you'll need a 2 speed flick ( MGB one will do) or rocker switch, or the park circuit work function.


You can use the existing green wire as the 12v supply obviously and the back wire as the earth.


Run three new wires from the plug to the dash switch. Correct colours are red/light-green (1st speed), blue/light-green (2nd speed) and brown/light-green ( park).


The correct switch has an internal connection that connects the 1st and park circuit in the "off" position and enables the motor to continue to run until the ramp opens the park switch and it stops.
Steve Smith Midget 1500

Many thanks for the info on the wiring.
Regards Slowly
Slowly

http://mgaguru.com/mgtech/electric/et218a.htm

Wiring and switch clearly explained
Dominic Clancy

This thread was discussed between 07/11/2016 and 17/11/2016

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.