hi Spider2-
Series 1 motor: on my motor, and also on the wiring diagram, you've got 4 wires connected to the motor.
Black - EARTH
White - up/down
Brown - up/down
Grey - +ve 12v
Ive written "up/down" against both WHITE and BROWN because I cant remember which is which
but the idea is that one of them controls the UP and therefore the other is DOWN! But theyre both +ve12v.
Your question about the GREY wire: yes - positive 12v! My understanding of electric motors is limited but the idea is that you have field and armature windings....the grey feeds the armature I believe, the white and brown feed the feed coil windings which are flipped ia the white/brown wire to give you the ability to change direction....someone more knowledgable can explain that better than I....
I believe the motor will work without the grey wire....I might be wrong about that....but I think it will, but maybe with less power.
What follows is the approach I took. Im sure you're way more knowledgeable! I have a limited understanding of car electrics, so I adopted a very simple approach....
(this is just about seeing if the motor works as opposed to creating a new circuit involving Relays)
First thing I did, is take the motor off the car - which is pretty simple (4 screws and that "stiffening arm") - and then test it....
I put mine in a small vice, then connected it to a spare battery I had.
If you connect GREY&WHITE to 12v and BLACK to earth = motor turns one way.....BROWN&WHITE to 12v and BLACK to earth, it should go other way....
(You can do the same thing without removing the motor of course - in situ)
If that works....put it back in car...
I then tested my motor (with hatch open) with my spare battery and test leads in-situ.....youve now got the limit switches to deal with....make sure the limit switches are connected to the correct UP or DOWN!
So now....with a bit of luck....youve got a working motor, with working limit switches....
Obviously you may have some "mechanical" reason why the motor isnt working correctly at this point...as in, maybe the "gear" is jammed or the thread stuck etc...
Maybe the hatch now works when you use the dash switch....? if so, then you can ignore the next bit but start thinking about using RELAYS to avoid the AMPAGE to operate the switch going through the expensive Ducellier switch (which is fragile I understand)....
Then, next step IMO, check that the wires coming from your Ducellier switch are good. you should have 3 wires coming off that switch (thats the BROWN, WHITE and GREY)....and of course, youve got power going to the switch.
If you take that fascia panel off, you then (with the motor back on the car - with hatch window open) have access directly to the wires connected to the switch.
You can test the continuity of the wires going to the hatch from the switch...and you can also, using your test leads, connect the same wires together WITHOUT involving the switch...just hot wire them together...as before power to GREY&BROWN or GREY&WHITE.....make sense?
If that works, and it doesnt work when you connect them back to switch, then you know youve got a problem with switch....
You can also check that the switch is doing the right thing of course with a meter and using the continuity function....
hope that helps
rog