wiper motor variants

Post by **57traveller** » Fri Jul 16, 2004 8:51 am

The "self park" stopped working on my saloon's wiper motor, not the end of the world I know, I tried cleaning everything up on the switch but to no avail. Fortunately I had a spare motor assembly which is now fitted and working fine.
The motor now fitted is a 100 deg sweep unit same as that removed ( stamped on large gear). There does appear to be two different types for the Minor 1000. Pre Oct '63 with either 100 or 110 deg sweep or post this date with one sweep angle option. Does anyone know if the variation coincides with the change from "clap hands" wipers to the more conventional (boring!) type and why there are two angle options?? Or is there some other reason. The self park mechanism also seems to vary depending on motor type. Both my cars have the "clap hands" wipers but the Traveller's wipers seem to have a larger sweep, I wonder if someone has fitted the later type motor? Any ideas please. I will remove the top and look at the gear though.
Also any ideas as to what may be wrong with the self park?

Post by **Gareth** » Fri Jul 16, 2004 10:35 am

I think the different sweeps would be due to the change to boring wipers - the passenger one must travel slightly further than the driver's one to give a little overlap.

The difference in sweep on your two clappers, if you'll pardon, is probably due to more wear in the wheelboxes/rack. There is a quick fix that you can try, but I forget what it is... might be something to do with turning over the large cog inside the wiper motor, but I'm probably wrong...

Post by **Kevin** » Fri Jul 16, 2004 11:13 am

might be something to do with turning over the large cog inside the wiper motor, but I'm probably wrong...

No Gareth you are right as that works on the later wiper motors as the wear is normally only on one half of the gear and turning it 180 degrees gives it an unworn section to work on, I have not worked on the earlier ones but I would think the same pricepal should work, but the motors are different as I read an article on converting to 2 speed wipers and it said it was easier to do on the clap hands wipers due to the different sweep involved, I think it was in the Owen Burton book.

Post by **57traveller** » Fri Jul 16, 2004 11:19 am

Thanks Gareth, I think you are probably correct, I suspected it was something to do with the change in wiper configuration. I'm sure replacing what was already there should be fine. No I don't think it is wear causing both wipers on the Traveller to move a larger angle, there is negligible lost motion and free play evident. I will check what is stamped on the gear, could be 110 degrees sweep and possibly it should be same as saloon (100 deg.).
The fix for wheelbox pinion wear is to remove the cable (rack) and turn the wheelbox spindles through 180 deg. then refit the cable, (on the clappers) just hoping that nobody has done it previously

It worked a treat on the saloon when I did it.

Post by **57traveller** » Fri Jul 16, 2004 12:45 pm

I think we posted together Kevin, hence the repeated 180 deg. spindle shift.
I've checked and the Traveller's wiper motor gearbox doeas have a 100 deg. pinion. So probably correct. I will try turning the wheelbox spindles anyway, can't do any harm.
Any suggestions re the non operative self park on the original motor would be appreciated if anyones had similar. Beginning to think it may be something internal with the motor.

Post by **woo** » Fri Jul 16, 2004 12:55 pm

Ray Newells' Original Morris Minor says regarding the 948 Wipers:

"Two types of wiper motor were used, both being fitted in a new exposed position in the engine bay. An improvement on the earlier mounting under the fascia, this new position allowed much easier access for maintenance. Lucas model DR2 was replaced by model DR3A in November 1961 at car number 939695, the DR3A keeping the 100 degree angle of wipe introduced in later versions of the DR2; on the 1000's introduction in 1956, the angle of wipe had been 110 degrees. The 'clap hands' action continued in use."

Post by **57traveller** » Fri Jul 16, 2004 2:32 pm

Thanks for looking that up woo, I never thought of consulting my copy first!

Wonder why they reduced from 110 to 100 deg.? That's what I read it as anyway. Originally 110 with the DR2 which I guess my Traveller should have ('57) later DR2's adopting 100 which continued with the DR3A.

Post by **Gareth** » Fri Jul 16, 2004 2:39 pm

Maybe there were problems with the wipers flying off the edge of the screen at high speeds, or when the rack became worn...

Nice one, Woo... ;)

Post by **woo** » Fri Jul 16, 2004 4:40 pm

Gareth,

I used to have an old '57 4 door with plenty of play in the wiper system and at times it did just as you say it 'flew off the edge' keeping the windscreen pillars nice and dry... generally when it was raining heavily and the screen was well lubricated with water.

Woo

Post by **Pyoor_Kate** » Fri Jul 16, 2004 5:55 pm

My '69 four door's wipers, when it's moderately wet and they've been going for more than a few wipes hit both the edge of the screen rubber and the bottom edge of the windscreen.... I've always found it a rather endearing charateristic (unlike the tchuck noise which appeared this morning when I started my wipers and intermittently seems to be occuring at the start of a stroke).

Post by **woo** » Sat Jul 17, 2004 1:27 am

There's a pretty comprehensive document about the operation, servicing and testing etc. of the Lucas model DR2 at this URL:

http://www.ahsdc.org/2003/wiper.htm

I don't know to what extent the model DR3A differs but it might be enough to get you on the right track with the self parking problem.

Woo

Post by **ColinP** » Sun Jul 18, 2004 6:57 pm

The self-parking device (it's in interrupted contact ring inside the cover/ on the rotting cog) is probably going to be mechanical (or bridged contacts).

The self-parking device should have a power connection (permanetly live when ignition turned on) It relies on the break in the ring to stop power going to the wiper motor so that it stops at one point. The wiper switch in the dash provides power as well (but not interrupted each revolution). chekc the contacts on the device - I recall mine being brass, so it possible there's dirt - or metal bits - or whatever causing the problem.

Colin

Post by **Multiphonikks** » Sun Jul 18, 2004 9:14 pm

My wipers got changed around when the Autoglass guy replaced my screen. Not only that, but I can't get one of them off now to switch them around again.

... grumble...

Post by **57traveller** » Mon Jul 19, 2004 9:02 am

57traveller wrote: I tried cleaning everything up on the switch but to no avail.

Tried that Colin, thanks.
It's a continuity breakdown internally, all checked with a meter. Unfortunately not the small wire that runs through the motor from the self park contact assembly. Probably something I don't have the equipment to find and repair. Had the motor adrift and there's nothing obvious. It's not done too bad though, a DR3A unit stamped 2/62 same date as car build, must assume it is the original.
Thanks for the link woo. One of the differences between the two could be the self park switching method. Looks to be different on the DR2

Post by **rayofleamington** » Mon Jul 19, 2004 6:45 pm

Probably something I don't have the equipment to find and repair

Hmm- if you have access to a voltmeter then it should be traceable and repairable.. The only additional tool you might need would be a soldering iron.
They really are pretty basic stuff - I was impressed how little there was inside when I took my last one apart. It will either be a duff wire a duff joint or something wrong at the brass contact/cutout plate - From memory, there's nothing else in there really..
As the motor is working then the brush holders / commutator etc should all be in order.

Post by **57traveller** » Tue Jul 20, 2004 11:09 am

As you say Ray, all fairly basic and everything's been cleaned where possible and looks fine. I may just try resoldering the two ends of the wire that's routed throught the motor from the top of the self park switch cover, soldered joints sometines deteriorate. The big problem is trying to get decent contact points to check the continuity. One occassion no continuity, ah, that's it! check again same place and there's continuity. I'll keep trying - there's no rush.

Post by **57traveller** » Wed Jul 21, 2004 8:46 am

Found the fault to be the limit switch contact "arm". It's lost it's "elasticity" and was not making contact with the disc in the cover. Careful bending made the contact but after a couple of minutes running it reverted to previous position. Probably very tired after 42 years! I can utilise the unit for parts if required.
At least I now know how it all comes apart!
A volt meter is of no use for testing Ray, the two most important readings required are current flow and resistance. A voltmeter would be fine for determining whether voltage is reaching the motor.

Post by **rayofleamington** » Wed Jul 21, 2004 11:53 am

the two most important readings required are current flow and resistance.

maybe I should have said multimeter. Mine does current and resistance as well as volts

Post by **57traveller** » Wed Jul 21, 2004 1:01 pm

A very useful instrument Ray even a cheap version is good enough for basic testing.
After finding the problem I used a couple of lengths of wire with crocodile clips at each end and connected to a 12V battery and each relevant motor terminal in turn to test.
The loss of "spring" in that contact component is one to bear in mind if the same thing happens in the future.

Morris Minor Owners Club

wiper motor variants

wiper motor variants

Re: wiper motor variants