Wipers Work Backwards!

SydneyRoverP6B

SydneyRoverP6B

Well-Known Member
Staff member
My windscreen wipers stopped functioning while driving on a rainy day recently (is that not always the way!). I checked the windscreen washer motor, and it worked so that precluded the fuse as the culprit. So out came the wiper motor, and upon removal I discovered that the carbon brushes were heavily worn, one essentially at its limit of travel.

I would like to replace the brushes with new items. Does anyone know if they are available and if so who might have some?

In the interim I decided to fit a replacement wiper motor that I obtained from a wrecked P6B. I plumbed it in, turned the wiper control knob and then to my horror the wipers went backwards,.. :shock: ..shooting off the screen down onto the valance in a tangled mess.... :evil:

Luckily no damage was done to my wiper arms or the valance. I pulled it all out again, the armature cover was as it should be, not 180 degrees out of alignment which will indeed make the motor run backwards.
I checked the wiring to the carbon brushes which was the same as on my original motor, so what gives?.. :? I cannot plug the wires into the motor incorrectly as the plug only fits one way.

Is there an adjustment that needs to be made within the wiper gearbox? What should I be looking for?

Please can anyone help?
Any help offered will be greatly appreciated.
Thanks in advance,
Ron.
 
Probably your replacement motor was out of a LHD car, or at least a car that had the wippers parking on the left.
If you replace the big crown wheel with the one of your old motor it will sort it.
In any case test it before you fit the wiper arms.
 
Hello Demetris,

Thanks for the reply. :)

I did remove the replacement wiper motor personally from a RHD car, so unless it had indeed been changed in that car previously for a LHD issue,... :?

I'll check the big crown wheel in each wiper gearbox and go from there.

Cheers,
Ron.
 
The story continues...and so does the frustration... :evil:

I removed the armature and cover from the second wiper motor along with the three carbon brushes and fitted them all to my original wiper gearbox assembly.

I cleaned the 35 years of sticky dust impregnated grease off the entire thing so now my wiper motor and gearbox assembly look just like new. Upto this point I felt quite pleased.

I fitted three new rubber mounts ready to accept the motor and then eased the cable drive through the tube engaging each wiper box in turn. Connected the wires to the delay (in the right order as I had marked them prior to removal) and plugged in the main supply wires to the motor.

Turned the switch to slow, wipers work correctly, to fast..also correctly. Now the problem. Turn the switch to the left to initiate delay and...nothing... :evil: So I removed the delay unit and fitted a new one,..just in case. Reconnected wires....turn switch to activate wiper delay and.......nothing.. :evil:

Oh yes,...the automatic park feature that they are supposed to exhibit,..well that is not happening either... :evil:

Before the wipers stopped working those few weeks ago while driving in the rain,...all the functions that the wipers possess worked correctly,...and now,..hmmmm.

I feel seriously displeased.

Please...does anyone have the solution to rectify the problems, apart from taking the motor out and throwing it in the bin.

Many thanks,
Ron.
 
DaveHerns wrote,...
I would guess the self parking switch is not working properly
Click to expand...

Hello Dave,

You are right on the money!! I completely dismantled the gearbox assembly and removed the self parking switch. Upon inspection the moveable contact which operates via the cam on the gearwheel actuating a piston had broken.. :(

No doubt this is also responsible for the failure of the delay mechanism to work.

Ron.
 
I am extremely pleased... :D :D :D I have fixed my wiper motor and the electrical logic works exactly as it should do. :D

I removed the park switch as it is referred to in the parts book from the second wiper motor and fitted it into mine. My wiper assembly now consists of its original gearbox and parts within, supplemented by the armature and armature cover, brush assembly and park switch from the second wiper assembly,...ie the unit that worked backwards.

There is no difference between the park switches or in the way the connections were made between the switch and the brushes. Armatures and armature covers are also identical.

With new wires installed (the original wires were in an appalling state,..heat damaged insulation and the copper strands that compose the cores just fell apart during handling.. :shock: ) between the park switch and brushes, all soldered up and everything back together, reinstalled into my Rover and the operation is exactly as it should be... :D

I have no explanation as to the reason behind the spare wiper motor when initially installed for working backwards... :shock: The gearboxes between each are identical as are the large nylon wheels and the way in which they operate with regards to their respective park switches. This will remain a complete mystery to me.

Ron.
 
ghce wrote,..
Just a thought , maybe the donar car wiper unit was positive earth?
Click to expand...

Hello Graeme,

Well the donar car was an English import as opposed to one assembled in New Zealand and the battery was connected in the traditional manner...ie negative earth.

Even if the donar car had been set for positive earth running, should not the wiring within the wiper motor be the same regardless?.. :? As it transpired..it was the same.

If I had repositioned the wiper blades on their respective wheel boxes to alleviate the problem,..that would have been fine while in operation, but as soon as the system was switched off the blades would park right up on the screen...one right in my line of vision..... :evil: ...a receipe for raised blood pressure if ever there was one.

Ron.
 
SydneyRoverP6B said:
My windscreen wipers stopped functioning while driving on a rainy day recently (is that not always the way!).
Click to expand...

Hi Ron

You probably wouldn't notice if they failed on a dry day. :D

Seriously though - when you fitted the replacement motor, how do you know it was at the park position? It could have been half way up the screen on the down stroke which would cause the apparent reverse operation.

Just a thought

Richard
 
you may have got some one else bothched repair, I have not personnaly taken apart the P6 wiper motors but have repaired and supressed many over the years all it takes is the parking gear to be installed 180 out or in other units the gears incorrectly synced.

Graeme
 
quattro wrote,...
when you fitted the replacement motor, how do you know it was at the park position? It could have been half way up the screen on the down stroke which would cause the apparent reverse operation.
Click to expand...

Hello Richard,

After the initial mess with the wiper blades ending up on the valance, I applied a piece of electrical tape marked with an arrow to the wheel box dome,..where the wiper arm would normally reside. When activated I could see by the direction of the arrow the way in which the blades would be running, and where they would be when parked.

Ron.
 
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