Window motors

[William2]

On my S4 Elan the window motors are slightly different in that one has a red plastic gearbox part and the other is yellow. Does this mean that the two units are different?

[billwill]

It is unlikely that they are significantly different. Are the gearbox shapes identical?

[oldelanman]

On my S4 Elan the window motors are slightly different in that one has a red plastic gearbox part and the other is yellow. Does this mean that the two units are different?

The motors are not handed, they are simply windscreen wiper motors 'borrowed' from Ford. Perhaps the one with the yellow plastic cover is a later replacement - mine both have red plastic covers.

[billwill]

Is the gearbox a Lotus addition, though, to the Ford motor?

If so Colin Chapman probably found a plastic moulding firm that made them cheaper, but used yellow instead of red plastic.


Without pulling the door panels off to check, I can't be sure but I think both my window motor gearboxes are black or dark brown.

[oldelanman]

Is the gearbox a Lotus addition, though, to the Ford motor?

I think the only mod Lotus did to the standard Ford motor was to fit the two pronged drive lever which engages with the nylon window cable drive spool in the door, the motor is otherwise a standard wiper motor. The (red) plastic housing on the gearbox encloses the slipring mechanism for the self park function of the wipers and would have been original.

Without pulling the door panels off to check, I can't be sure but I think both my window motor gearboxes are black or dark brown.

You are right Bill, there is a brown plastic top on the red housing which covers the spade connectors to the slipring.

[worzel]

Hi

Just an update on my original question- the circuit I posted does work (my fault, I should have checked more carefully).

On a related note, I know the motor works without an earth but on this car (a 72 sprint I've had since 1978) I assure other readers that the two door motors were/are earthed and the earth wires were definitely connected to an earthing point. I don't think the previous owner (the very first owner) was a "hands on" type of owner so I can only assume the car came with earth wires as std. I did notice however that in the 72 print works manual the wiring for a S4 does show an earth attached to the motor(s).

What started this process was the intermittent operation of the window on my side, up always worked but down was hit and miss. I had actually stripped both motors around 2 years ago and for quite a while both sides were fine but around 6 months or so ago the afore-mentioned problem started to crop up. Usually I leave the driver window open about a half inch when parked up and when down started misbehaving I used to raise the glass then found that down worked ok. I assume now that raising the glass moved the internal contacts to a better spot enabling down operation.

I had exactly this problem on the Excel I once owned. The driver window would not operate without the occasional (regular) strip and clean of the motor (the commutator always had dark deposits on it which I assumed interfered with the contacts). After repeating this exercise every couple of months and wondering why the passenger side never gave any problems I eventually discovered that the earth between the driver motor and the steel door beam wasn't connected. Re-connecting cured the problem until I sold the car (8 years later). Just as test a couple of months later I had a look at the internals of the driver side motor and found that the commutator was still clean so presumably the earth not being connected and the deposits inside the motor had some sort of link

A I said in the earlier post my initial test of the motor when I first started this job involved fitting a working earth and immediately the motor worked in the down direction (the circuit that wouldn't work) so maybe on my car (not necessarily anyone else's) the motors to be earthed although I can't think why that should be. I did notice that the commutator was soiled with deposits so just maybe the inoperative earth and this problem are/were linked. We shall see in due course.

Again, thanks for all of the input.

Regards

John

[oldelanman]

Just an update on my original question- the circuit I posted does work (my fault, I should have checked more carefully).

John, I think perhaps you have posted to the wrong thread. Did you mean this one ?...electrical-instruments-f38/wiring-circuit-for-relays-the-window-motor-layout-t27854.html

However.......

On a related note, I know the motor works without an earth but on this car (a 72 sprint I've had since 1978) I assure other readers that the two door motors were/are earthed and the earth wires were definitely connected to an earthing point. I don't think the previous owner (the very first owner) was a "hands on" type of owner so I can only assume the car came with earth wires as std. I did notice however that in the 72 print works manual the wiring for a S4 does show an earth attached to the motor(s).

The wiring diagram does show an earth connection but it is misleading.
In the standard wiring configuration (without relays) the motor is both powered and earthed via the window switch on the dash, the switch reverses the connections to achieve the raise and lower functions. The motor casing is grounded to reduce radio interference and this is what's shown in the wiring diagram - this connection plays no part in the motor operation.