One for the brains trust...

I'm trying to hook up my 2 speed wiper motor but am getting nowhere. I've followed the how to guide but it hasn't helped.
I think I may be missing a wire....and my sanity

Here is what I have:

At the wiper, 4 wires: Black, Red/Green, Green, Black/Green.
At the switch, Black, Red/Green, Black/Green.

Switch is definitely a 2 speed switch (part numbers are 35927/P94317) and has 6 terminals numbered 1,2,4,6,7,8.

When I hook it up as per the how to guide for 2 speed wiring, all i get is a single speed in the middle switch position with no parking. Switch in bottom position turns the motor off, again no parking. I have made sure to earth the motor body to the car body securely as well.

In the how-to wiring diagram, there looks to be a 4th wire going from the switch to the motor which I seem to be missing from my loom. I tried just running a temp wire to see if I could get it working but no go.

I've tried multiple combinations of wiring as well but still no joy.

Any suggestions folks?

You need a Blue/Green wire from terminal 8 of the switch to the wiper motor (as shown). If you don't have one, run one.

Are the 3 copper fingers making good contact with the slip ring underneath?
Is the slip ring corroded at all?

The last 1% usually causes 99% of the stress!

After making a sacrifice to the Lucas Electrics gods, I pulled the wiper motor apart and checked/cleaned it completely.

Seems to have done the trick as the bloody thing works now.... I did have to add a wire from switch pin 8 to the motor, but I’ve got 2 speeds and self parking!

Of course, else you don't get the second speed.