Hi,

I'm having some problems with the wiper motor on my 1959 MK2 jag. Its a RHD car although it was originally LHD and converted when it was new back to RHD.

The motor is working on both speeds but when it comes to parking it parks halfway up the screen.

Looking at the wiper blades it wipes up from the screen rubber to around 120 degrees and back when its running, when I switch it off it then changes to starting at around 150 degrees and parking at around 30 degrees.

What I have seen is:

When running in normal mode or fast mode the drive cog in the motor runs clockwise.

When in park mode the drive cog runs anti clockwise.

The linkage connected to the wiper motor cog has an eccentric cam on it when means that when it runs anti clockwise the arm in the motor becomes longer hence the change in sweep angles.

I think this would be correct if it were a LHD car as the wipers would park on the left but as its RHD the wipers need to park on the right (the pre-strip down photos show that this is the case).

Does anyone know what I might have done wrong?

 

remove the wiper arms and run the motor without the arms.

Allow the motor to park, then reinstall the wipers again in the parked position but do not let them touch the glass, place them in the "folded out" position. (just in case they decide to sweep into the cowl and cause damage to the paint and everything else in their way).

run them again to see if the park correctly.

 

see if these two documents are of any help

 

Thanks Jose, those docs are really useful.

Hopefully they will assist Homersimpson too.

 

Thanks Jose, that's really helpful.

Looking at the parts catalogue the bit which I think is causing the problem is as the image below, interestingly this has two part numbers and i'm wondering if one is LHD and one RHD as the eccentric cam needs to work in opposite directions for each application. Mine seems to be working as a LHD car at the moment. i.e. it moves further to the passenger side of the car (RHD) when it parks.

I will check that I haven't mixed this part up when rebuilding the motor as I did use bits from a spare I had which was from a different car (single speed DR3).

 

Hi,

So I went and had a look at the two linkage arms I have and they are both the same, for good measure I swapped them over but its still the same.

I found the link below which shows how they should work, if you can imagine with mine in normal running the blade starts horizontal with the window rubber and only goes to around 120 degrees, when you switch it off and it goes to park it then goes upto around 150 degrees and parks at 30 degrees off the rubber, it seems to be working backwards to how it should be.

 

frankly I think they are woking as supposed, i.e., the driver's side section is being fully wiped.

if you want more wiping towards the left side (passenger side), then raise the wiper arms in one quarter of an inch increments.

does you motor have a thumb knob in the front of the motor to adjust the Park position?

if yes, you might be able to adjust the sweep through the knob, making it park a little higher.

The ironic thing is that these wipers in the old small Saloons sweep a lot faster than the wipers in my 1984 XJ-6 which are very anemic. (slow).

 

Looking at the Lucas info Jose posted, most of the motors have a 120deg wipe angle, some do have a 150 deg wipe angle, do we know which DR3 model number in fitted in the MK2's ?
The part no from SNG does not tie up with the Lucas part numbers as it states 73144 or 73145, but I can't find those numbers in the Lucas info, I have not looked at the parts Catalogue yet to cross ref.

 

Just checked the parts Cat, the motor is 75310 RHD and 75311 LHD both have 120 Deg wipe.

I assume the 2 motors run in opposite directions (possibly), the wiper motor is mounted in the same place on LHD and RHD if my memory is correct.

If the wipers worked before Homer, then I assume you have the correct motor, and that it is the park position that needs adjusting. The 120 deg sweep appears to be correct.

 

Hi the video I posted was one I found on youtube, this is how they should work but mine don't do this, they work as described.

 

Hi,

I have never seen the wipers work before but the pre-strip down photos show that the blades were on the correct side.

As above if you switch the wipers off when the blade is traveling upwards they park on the rubber, if you do it when they are travelling downwards they park about 30 degrees up the screen.

If the wiper blades parked on the other side of the screen (i.e. left side if you are sitting in the car) then it would all work perfectly but that would be a LHD car. I guess the question is whether the motor is different LHD to RHD (i.e. it turns a different way) or whether the linkage I posted above with two part numbers is different LHD to RHD, if I could swap this over it would again work perfectly. Does anyone have a LHD wiper motor and if so can they photo the rear of the internal linkage with the eccentric cam in it?

 

That's why I asked the question, if you have the LHD motor fitted RHD then you will have an issue, if you knew they were working before then I would assume the motor is correct but it not parking correctly.

Do the wipers go clockwise to park or anticlockwise to park ?

A LHD motor should go anticlockwise to park and RHD clockwise to park.

If I understand you :- if your wipers are turned off whilst traveling anticlockwise then they go back (clockwise) to park on the rubbers, but if they are traveling clockwise when you turn them off, they stop at 30deg away from the rubbers, I'm just making sure I have fully understood ?

Can you see a part no on the motor, just to be sure the LHD issue is not a red herring.

 

ok, I understand now.

my '65 S type has the same motor, car is Left Hand Drive, the wipers are wonderful, better than the '84 XJ-6 wipers, and it has a Thumb Knob to adjust the Park of the wipers as low or as high as I like.

Otherwise I can't diagnose what is happening with yours, other than guesses, for example, is the Cable the original cable? is the cable too short?

 

The motor number is 75310B, not sure what the extra B means.

I have fixed the problem with the motor by swapping the wires inside that connect to the brushes, by reversing the magnetic field in the armature but leaving the field in the coil the same it runs in reverse to how it was previously and all is now correct.

The motor now runs clockwise to park.

Not sure why it has ended up like this though?

 

Just took some pics of mine, same number, but mine has a J after, interesting it has a PARK <--<< marking, which seems to indicate it parks to the left, which when viewed from the front of the car would be correct.

On the LHD, what is the part no. and which way does the PARK marking point.

Maybe the motor was wired incorrectly in the first place before you took it out ?

 

my S type's left hand drive wipers park towards the DRIVER side, but the XJ-6's left hand drive wipers park towards the PASSENGER side. Go figure!!

 

I have attached a photo of mine which also indicates that the blades park to the left.