Wiring for series 1 wiper motor

I am completely flummoxed by the wiring for this motor. Here’s what i have done so far
Completely rebuilt the motor and bench tested it works fine including that the eccentric cam does as it should and the rack moves further in reverse than it does forward. The limit switch checked and works as it should.
Put it into the car and it runs beautifully at both speeds but wont self park…
I read that when switched from slow speed to stop the dash switch reverses the voltage so should make pin 1 on the motor 12v positive, which it does, and pin 5 negative, which it doesn’t, hence it doesn’t reverse and the self park system doesn’t.
Ok now it gets fun, my question is how does this motor get its earth in any position? I cant find an earth return in the wiring diagram. I am using diagram W54955069 in the Jaguar service manual. I have cleaned and tested the dash switch, it works fine, I have the following connections in the switch.
Off pins 5 to7 and 6 to 8
Slow speed 3 to 5 and 4 to 6
High speed 1 to 3 and 2 to 4

It runs in both speeds thus at first sight since to run pin one on the motor needs to be earthed, it looks like the white/ light green on pin 1 gets an earth via the black wire on pin 4 in the plug which in turn connects internally within the limit switch to pin 2 the brown/light green but it in turn only goes to pin 8 on the dash switch and nowhere else. What am I missing? the drawing of the whole switch system shown no earth return that I can find. Is there something missing on the drawing?

Any help appreciated

Ian

Since you are well into it; I can just give you some food for thought, Ian…

In ‘high’ and ‘low’ speeds the ‘park’ switch is bypassed - power and ground is made at the stalk switch. The ‘high’ and ‘low’ motor brush is powered - the ‘third’ brush is grounded in the stalk switch.

In ‘off’; power is delivered from the stalk switch to the ‘third’ switch. Ground is provided by the park switch (to the ‘low/high’(?) brush). until wipers reaches the parked position - motor direction reversed. At parking, the park switch switches (from ground to the previously grounded ‘low/high’ brush) - applying the stalk power to that brush. With both brushes at 12V - the motor stops.

As an aside; if the excentric cam in the park switching was misplaced during rebuild, or malfunctions; the self parking will fail.

Frank
xj6 85 Sov Europe (UK/NZ)

Here is the Lucas wiper motor wiring schematicLucas16.pdf (255.6 KB) I have found helpful.

Thanks Roger that is exactly what I needed and shows 4 black as being earthed. The manual circuit diagram does not show the earth on that wire. Mine wasn’t, now is and now self parks as it should, unfortuanately at present on the wrong side but that’s an easy fix.

Thanks again

Ian

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That means that the cam operating the parking switch is reversed, Ian. A month ago the RHD/LHD wiper parking conversion was presented…

Look up ‘LHD versus RHD wiper motor parking’ - problem and solution described…

Frank
xj6 85 Sov Europe (UK/NZ)
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Hi Frank
That thread was mine, I am now back from Oz to Europe and put in the motor I bought in NZ. It is now working ok and I have changed the parking side. Now working well.
Thanks

Ian