Lancia Motor Club

Could someone explain how the electrical circuit works on the rear hatch of a Fulvia Zagato please?

There's a SWITCH on the dash (UP to raise hatch, DOWN to lower). As I understand it, 1 hot wire (Black) comes in with 3 wires coming out of it....see attached pic. They're colored : white, brown and grey.

Those 3 wires go straight to the motor - second pic....

My understanding is that when 1 of those wires (Brown) coming into the motor gets 12v then the motor will turn one way....then the when switch goes the other way, the White wire gets 12v and it turns the other way....

The motor seems to behave itself in one direction....not so good the other way....but maybe Im doing something wrong when I test it....???

What is happening here? Are these circuits somehow switching the polarity of the power going to the motor to switch its direction?
Any help welcome!
thanks
rog.

If you pull the switch from the dash and check its logic it is doing what you say. Problem is the contacts carbonise. You can dismantle the switch with absolute care to clean the contacts but be warned easy to lose small springs and bras fingers... Contact cleaner only works for a short time....

Thanks Tim.....

If I want to test the motor in isolation (take the switch out the equation)....then Ive got those 3 wires going into it (Brown, White & Grey)....

Would I connect power to the GREY going into motor, then if I add 12v power to the BROWN it should turn one way? then if I put 12v to the WHITE the motor would turn other way (But GREY always has 12v)??

The motor will start moving up and then stop if the 2 end-of-run switches (connected to the motor at the back) work fine (same for coming down). These are mechanical switches and if worn they can be replaced. Andrea

Thanks Andrea
The limit switches seem to be doing there job....so that part is okay. My problem seems to be the motor itself....which I dont think is original. It only has the 2 wires going to it.....the original has 3 (including the GREY....mine just has the BROWN and WHITE connected).
Do you have a picture or can you confirm that?

The switch seems to be behaving too : if you push it up you get 12v to the circuit raising the window and vice versa for the other "down" circuit...

To activate the motor, it needs a good earth. Is this present? I repaired mine a few years ago and ufortunately I don't recall the wiring now, however in general on the Fulvia electrical items are always connected to (+) and are activated when a switch goes to earth. I can check the wiring diagram if you don't have one handy, Andrea

If you had a moment to take a picture of your motor and the way its wired, that would be extremely helpful...
Do you have 3 wires plus the earth to yours ?

Mine does seem to be earthed - but it doesnt seem to be earthing back through the switch on the dash (as your comment would imply).....
Not sure if its the original motor, so trying to figure out that out

It is not easy to take a picture with the motor in the car. There are red (two), white and brown wires that I tried to photograph but so far my camera is unfortunately giving trouble to download the images, I will send them to you once I manage to solve this problem. Perhaps you can trace the connections using the wiring diagram of the car, Andrea

pics attached

one more

Thanks Andrea
The original wiring diagram doesn’t show the RED wires but it’s still very helpful to see
Thank you!

Hi
I have a problem with my rear window motor as well. It works sometimes slowly.  I think it is a voltage problem.
Battery voltage. 12.5v
Fuse box.           12.3v
Switch output.    11.3v
Motor.                10.3v

I guess the motor does not like 10.8 volts but it does not work with engine running either although I have not tested the voltages with the generator on line. Biggest voltage drop is through the switch
So what is the cure?
1/ new switch:  Do not think they are available??
2/ rebuild switch. Full of perils, I have read
3/ modify motor to like 10volts?
4/ Put a relay in. Where is there 12+ bolts at the rear of the car,?
The grey wire from the motor to the switch has been disconnected with a PO labelling it ‘No Use’. That sounds Italian.
Help would be appreciated.

Thanks
Simon.

Hi Simon -

I’ve been discussing this issue with a number of people.
The general consensus is that installing relays is a good plan - by doing that you’re removing the ampage (necessary to operate the hatch motor) going through the actual switch...
That switch is prone to burning out - the contacts becoming carbonized by the amps going directly through the switch.

If you’re dealing with a series 1 car then you’ve got 3 wires going back to the switch - the GREY (+ve 12 volts for both UP and DOWN) and then either +ve 12 volts coming from either WHITE  or BROWN depending on if you’re engaging UP or DOWN.

The basic idea is to put another larger +12volt connection back there (ie. Add a 6 gauge wire or something) coming from the battery....then use that new power source to drive the motor. You’d use the original wiring to operate three relays - each pulling power off the new source to actually drive the motor.

Make sense ?
Rog.

This philosophy is used to imorove the 1600 electric door window function. The circuitry has been detailed in a VivaLancia article last year (sorry cannot recall which issue).

Thanks Rog. Yes a series 1 and yes all very logical and I think I understand it. However......... my grey wire from the motor has always been disconnected. It used to work badly but now not at all. In your post you mention the grey wire as +ve. Is that correct if the brown and white are also +ve?  I say the grey wire has always been disconnected but perhaps it just became disconnected when I pulled the carpet away.
I have a 4th black wire coming out of the motor with a a brass ring on the end. I am guessing this is an earth but a PO has written a note on it say ‘NO USE’
If my motor is toast can I use a series 2 motor?

Cheers

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

Thanks Rog, I pretty much have done all that. Tested the motor in my workshop (AKA the garden shed) and it work pretty well connected to a battery. Disassembled the mechanical bits, cleaned and lubed. It spins well on the finger wheel.
However, very strange. I remember now. The grey wire that should go to the switch was disconnected but had been connected to the frame of the screw jack with an electrical connection so it was never connected to the switch, but it did work in that configuration but badly.
I have checked for power on the grey wire and Nil volts, at least at the boot end, that could be my problem.
I will check at the switch.
Another thing is a PO took the limit switches out of the equation. Consequentially the motor would have hit the stops and caused it and the switch contacts stress. Limit switches work well but still disconnected until I sort the main problem out.
Cheers
Simon.

However, very strange. I remember now. The grey wire that should go to the switch was disconnected but had been connected to the frame of the screw jack with an electrical connection so it was never connected to the switch, but it did work in that configuration but badly.

If Im following you correctly, weirdly my motor was also set up that way - earthing it through the GREY wire. The BLACK was not connected to anything. It did work but, as you said, not well.....

Limit switches: ugh! As you mentioned, you really don't want to disconnect those - that little motor is going to stress out if it just pushes against the stops. Strangely enough my limit switches were the wrong way round! For example, when the hatch was at the UPPER limit the lowering circuit wouldnt engage because the lowering circuit had been cut off by the limit switch! Mad!

From what Ive read, and others comments, the Ducellier switch can "burn out" or start misbehaving because of the ampage going through it. Mine is not connecting the GREY wire terminal correctly - which it should connect when you push the switch UP or DOWN....however, as Im going to put the Relay system in (to avoid the ampage going through that switch), I dont think I really need that. Ill just drive the Relays at the back of the car with the BROWN and WHITE lines...which will also give power to the GREY wire going directly to the motor. Im going to use either 2 double pole relays or 4 single poles...

When I fitted the relays (4 - 2 each side) to the electric windows (same motor as hatch) they operate very fast- too fast for the mechanism. I would advise making sure the limit switches work and do their job or the motor will possibly de-thread itself... I have not yet relayed the rear hatch motor as I like the slow operation......

My limit switches work well and will reconnect them once the primary problem has been solved. Strange how the whole system seems to be wired contrary to the wiring diagram. My motor is earthed to the frame of the assembly via the grey wire and the black one is not connected to anything. One theory I have is the grey wire caused too high a field voltage and made the motor run too fast so people decades ago discovered that disconnecting it made it run slower. Just surmising.
I have good voltage on the brown and white wires at the motor end when the switch is operated up and down which should rule out the switch and the wiring. The motor works on the bench but not in situ. The motor I guess has to be earned to the frame of the car. This I assume is just done via the attachment but why the black wire disconnected? Logically it looks like it was once connected with the bolt that secures the bracing strut to the motor frame.
Keeps my mind busy in retirement!
Simon

Hi Simon - I believe that BLACK wire is the earth - per the original wiring diagram. Mine wouldnt work without it being connected to the body of the car via one of the 4 screws that attach the mechanism to the car. However, as you mentioned, mine was also originally earthed via the GREY and the BLACK was disconnected......I dont undertstand enough about motors as to why that would still work!

Thanks Tim!