Sabra Wiper Motor

Sabra Wiper Motor

For (almost 35) years now the Sabra wipers have annoyed me.

I had four problems with my wiper motor:

1. To put the wipers off I always had to wait untill the wipers were low at the edge of the windscreen to put the switch off.
If I didn’t, the wipers went to and fro for a second and then stopped half-way down on the windscreen.

2. I couldn’t understand why there were five wires going from the motor to the switch, certainly because it didn’t even manage to park properly (see 1).

3. As long as the wipers of my Sabra worked properly (disregarding the parking) I didn’t dare to open the motor or tinker with the wiring.

4. The wires from my wiper motor are all five brown, they connect to different coloured wires on the cable loom but I wondered how ever they decided in the factory wich brown wire to connect to wich colour on the loom.

Recently I found me a spare motor, a good switch and also a motor that didn’t work, so I could start dismantling these without risking that my Sabra would have to stay in the garage on rainy days.

When it’s about Sabra electricity: Geoff Cooper is the one to hire. Geoff made this diagram of the wiring and connections in the switch: Fig. 1

Geoff_visio_switch

With this diagram you should be able to check the colours to connect to which pin on the switch.
The “PIN” column shows the fixed connections in the switch.
The “CONNECTIONS” column shows the moving connections in the switch.
The “FUNCTIONS” column shows how the wires get linked in the (park-slow-fast) functions. This can also be used to test the motor when it’s out of the car (without using the switch).

I actually like the the next diagram more (Fig 2) where Geoff shows the insides of the motor and switch.

In the switch the narrow black lines are the permanent connections.

Geoff_visio_motor

This diagram makes (me) understand what happens:

Green always gets 12V and always connects to the brush of the rotor (over a bimetal to shut off when overheating). This safety device is often shorted.

In “Slow” the Normal coil gets 12V over the blue wire => pin 8 => 10 of the switch => green wire.

The rotor gets ground over the red wire pin 13 => 1 of the switch

The coil gets ground over the brown wire to pin 5 => 4 of the switch and then inside to pin 1

In “Fast” the Normal coil also gets 12V over the blue wire pin 8 => 7 => 10 and the green wire

The rotor gets ground over the red wire pin 13 => 12 and then => 1

But now the Normal coil gets its ground over the Boost coil through the yellow wire to pin 3 => 4 => 1

In “Off” the rotor gets ground over the “P”ark switch.

The Normal coil also gets ground over the Park switch over the red wire pin 13 => 11 => 10 => green wire

And the Normal coil gets 12V over the blue wire pin 8 => 6 => 5 and the brown wire.

The above diagram shows how the wiring should should be. It shows that the current through the stator coil flows the opposite way when in “Park”. Resulting in the reversing of rotation of the motor.

Switching the car from positive ground to negative ground doesn’t influence the working of the motor as this would reverse the current in both rotor and stator.

It also shows that when the switch is put in position “0” “Park” “Off” it doesn’t cut off electricity from the motor but it reverses the direction of rotation and then passes all control to the Park switch inside the motor.

Now lets have a look at the real stuff: (Fig. 3)

tec 011

You should read DR3 for the type.

The 1/63 would mean something like first week - month of 1963.

You see “PARK” and an arrow pointing opposite from the drive cable. This should indicate that this motor would park when the drive cable is pulled in at maximum (we suppose).

Don’t trust the arrow! This motor parkes with the drive cable at maximum out, so opposite of the arrow.

It’s easy to put the wrong crank cover on a motor.

But as it’s possible to reverse the parking switch, the arrow isn’t really important.

Fig. 4

Crank case cover removed: (and some spacers and springs that hold the crank to the nylon wheel).

wipermotor_park 001

You see that the motor shaft drives the nylon wheel; shaft and wheel turn in one direction when wiping, and in the other direction when parking.

Notice the mark: 140° on the nylon wheel, obviously the wiping angle. I’ve seen 120°, 130° and 140° on different Sabras.

The crank converts the circular motion into an oscillating linear movement.

The drive cable is not present here, the right part of the crank simply hooks into the end of the drive cable.

The park switch is also visible.

It connects the (originally black) wire from the motor to the ground of the motor.
It disconnects when the rounded copper lever is pushed up by a notch on the end of the drive cable.

This is why the motor must have its own ground connection (see fig. 2).

The park switch is here in position “Park out”. Fine tuning of the parking position is done by turning the knurled knob outside of the crank case. To switch to “Park IN” the parking switch has to be taken out and put in the opposite way so the lever would be pushed when the drive cable is pulled in.

I know (now) that I should have taken notes about the real “wiping” direction of the motor shaft. I’ll try to do one of these years.

Notice also the hexagonal nut down on the picture on the outside of the crank case. This nut locks a screw that prevents the shaft from being pushed out-in.

This is what you should see when removing the crank from the nylon wheel: Fig. 5

(From above to below)

Crank_original

Why make it complicated like this? Fig. 6 shows the same crank but the insert disk is in opposite position.

Crank_short crank_long

This is where the reversion of the turning of the motor comes into play:

The insert in the crank (where it hooks over the pin on the nylon wheel) is eccentrical, so left you see the crank in wiping position, the distance from driving pin on the nylon wheel to the connector to the drive cable is shorter than on the right picture.

By reversing the turning direction of the motor from wiping to parking the crank gets longer so the wiper arms go further (down-up).

Attention: you’re looking at the crank now from underneath, where it rests on the nylon wheel.

Indeed clever, this way of arranging for wiping and parking. If only the mecanics would have known how it worked.

We have no precise knowledge about it, but it early Sabras obviously had a one speed motor. Just guessing DR3A???

Fig. 7 also by Geoff shows how the engineers might have dealt with the different parking position for LHD Sabras and RHD Sabres.

Parking diagram

But this is not how it was done: all early cars (Sabres as well as Sabras) had the wiper motor on the right wing.

So perhaps they put the wheelboxes upside down: when the drive cable passes underneath the wheelbox the wipers park on the opposite side.

Why the motor was positioned on the left wing on later Sabras (also later Sabres?) is unknown.

I haven’t seen enough Sabres but I think the moving of the motor from left to right had nothing to do with the parking position.

For now we think that there’s possibly four different cars (regarding the wiper motor):

Wiper motor on right wing, parking right side of windscreen (sabra)
Wiper motor on right wing , parking on left side of windscreen (Sabre)
Wiper motor on left wing, parking on right side of windscreen (Sabra)
Wiper motor on left wing, parking on left side of windscreen (RHD) perhaps this one wasn’t implemented.

Jacques’ GT has the wheelboxes upside down (compared to his ST) and he has the parking switch changed to the “Park IN” position. But as I said, I didn’t take notes about the turning direction of the motors.

But on all other Belgian Sabras that I’ve seen:

The wipers make a wide movement, from the bottom of the windscreen to the left.

When you put the switch to “off” while the wipers are not very low the arms go to and fro and stop halfway the right of the windscreen.

The Park Switch is in the Park out position and the wires coming out of the motor housing are all the same colour – brown.

Did Autocars buy motors without wires (cheaper)?

Or did the engineers try to alter the parking position by changing the position of the wheelboxes as well as changing the wiring inside the motor? Hard to find out forty years after.

Anyway on my Sabra (and all Belgian Sabras that I know off) the motor turns the wrong direction. I.e. when I put it on for wiping the crank turns to it’s long position and the wipers go from all the way left of the windscreen to the bottom edge. When I put the switch on “0” or “Park”, the crank turns to its short position and the parking switch stops the motor when the wiper is only halfway down. If I adjust the parking switch to get the wipers lower the wipers don’t park anymore because the (now shorter) crank arm doesn’t reach the parking switch anymore.

So my only solution was to change the turning direction of the motor. Did this by switching the wires leading to the brushes alone. Fig. 8

Switch 004_N

It is not at all difficult to do. It is easy to take off the bottom end of the motor (it only holds the bronze bearing – no wires) and switch the wires leading to the brushes (see picture). You see the red and the green wire, these connect to the brushes. Invisible are two other wires connecting to the same soldering points. Switch the four wires two by two and the turning direction of the motor is reversed.

When refitting the bottom end of the motor don’t tighten the two screws too hard. It’s best to tighten them halfway, then start the motor and tighten them firmer one by one while listening to the motor, often if they’re too firmly tightened the motor gets stuck.

Conclusion: as always with Sabras there isn’t one proper way. Some cars have the wiper motor on the right wing, some have it on the left wing, some have the drive cable run under the wheelboxes, some above the wheelboxes. Some have the parking switch operated on the inside position, some on the outside. And probably some motors turn clockwise while wiping and some turn anticlockwise. Some have wiping angles of 120° some of 130° some of 140° .

Don’t be afraid of opening the motor. It really is simple and straightforward.

This is one of the often occurring faults: when the shaft holding the nylon wheel is stuck the motor won’t turn.

Easy to remove, if it isn’t stuck too hard – circlips and washers at the bottom.. Fig 9

The nylon wheel and the motor housing are removed here, on the upper side of the rotor shaft there’s an adjustment screw. It prevents the shaft from moving upward – downward. Fix is good for me (no axial movement) though one might think it wouldn’t be bad to give the shaft some play to get some impetus before starting to work.

The motor shaft is held by a standard bronze bush as well near the crankcase as on the rear of the motor.

It’s a bronze bush held to center by a star-like (diaphragma-like) spring. Fig 10

The rear of the motor: simply clean the collector to give some extra power – no problem should occur.

Fig 11

wipermotor9

Picture of the safety device: should get really hot before switching off.

Jacques had problems with the front bearing bush of his wiper motor:

Fig 12

wipermotor20

Parking by the drive cable:… THIS IS A RED WIRE most cars should have a black one !! Fig 13

wipermotorsports2

The switch:fig 14

Wiper_engine 003_S

Wouldn’t do no harm if – when you would be playing with your Sabra wiper motor – I certainly know nicer things to play with;

You would send me an Email stating:

I’m Xxxxx, Xxxx

Own Sabra Xxxxxxxx built in??

My wiper motor is on the L-R wing

It shows specifications :

DR3…………..

I have the two speed switch

The drive cable of my car passes beneath – beyond of the wheelboxes

The parking switch is on position IN or OUT.

While wiping the turning direction of the motor shaft – looking from brushes to nylon wheel is anti- --- clockwise

Parking and wiping goes as it should or is completely wrong by…..

If lots of you would respond to this question it’s not impossible that I would find a clue.

We think early Sabras only had one speed wiping.. If all of you would answer my request it wouldn’t be completely impossible that I’d find a LOGICAL explanation, not by myself, but by consulting all the other people that know ever more about the car.

It’s not difficult at all to remove the crank cover and have a look at what happens while wiping – parking.

If you have a wiper problem: by reading this article you might get enough knowledge to fix it.

And, after reading, by using your own technical knowledge and intelligence you’ll probably be able to repair the stuff a little faster.