Window lift motor replacement?

[Kevin H]

Does anyone have any experience replacing the window lift motors on earlier (409-411) V8 cars?

Anyone sourced any modern alternatives?

[Sam410]

Originally Posted by Kevin Howard

Does anyone have any experience replacing the window lift motors on earlier (409-411) V8 cars?

Anyone sourced any modern alternatives?

The motors for my 410 windows work well, but I have had problems with the microswitches. Few of the 409 and 410 had electric windows at all, and it was to special order only I believe. These earlier cars used a chain-driven Piper mechanism, as fitted to many R-Rs, Bentleys and Astons, which I understand to be completely different to the 411's mechanism.

I spoke to Bentley specialist Introcar when looking for new microswitches (which they couldn't supply), who said they tend to junk the Piper system and fit more modern motors when they have to fix them. Might be worth trying them for suggestions?

[geo]

Originally Posted by Sam410

The motors for my 410 windows work well, but I have had problems with the microswitches.

I only have experience with the later system used on the 412, but here the switches can also prove to be troublesome (as is the case on many other systems of the period). It is really worth taking them apart (watch for any springs and little ball-bearings!), cleaning them up with a contact cleaner (one of the glass-fibre pencils is also useful) and reassembling them — this always worked for me. The other problem on the 412 was that even the later type of motor got very wet and many of the connections suffered corrosion. After rectifying this along the same lines as the switches, I glued builders polythene inside the door to stop any water landing on the motors.

Originally Posted by Sam410

I spoke to Bentley specialist Introcar when looking for new microswitches (which they couldn't supply), who said they tend to junk the Piper system and fit more modern motors when they have to fix them. Might be worth trying them for suggestions?

As I currently have an R-type (anyone want to buy it?!!) I have had quite a few dealings with them and they are a pretty helpful outfit.

George

[RGSchmitt]

Hi all -

"The other problem on the 412 was that even the
later type of motor got very wet and many of the
connections suffered corrosion. After rectifying
this along the same lines as the switches, I
glued builders polythene inside the door to stop
any water landing on the motors."

Don't know if this applies, but an expert on
Imperial (Mopar) window motors found that the
window motors were corroding internally because
the hot motors drew in moisture when cooling,
which collected on the bottom of the casing and
could not escape. Fortunately, these same motors
were used in nearly all Mopars for about 20 years, so easily sourced.

There is also an Imperial owner who offers a
service to rebuild window switches.

Bob

[MYTA21]

Trsut my car, a 409, to have the odd ball units, ie the Piper motors! However that might mean some input from some RR contacts. These are chain driven- noisy. ( Sounds like a port cullis raising!)
Raising the glass is assisted by some coiled spring devices which resemble steel tape measures.

I have not taken anything apart yet, but the problem seems to be that on one window, the motor raises the galss to it closed position. For a couple of times, it will work up and down, never failing in an intermediate position. Then on closing, it fails to reopen-a click is heard.
Wind the screwdriver in the hole and it will work for a while.
So, am I correct in thinking this looks like limit switch?

[412usa]

Kevin,



I had the motors on the 412 rewound about 8 years ago and they still work fine. Is this an option?



Peter

[Kevin H]

Originally Posted by MYTA21

Trsut my car, a 409, to have the odd ball units, ie the Piper motors! However that might mean some input from some RR contacts. These are chain driven- noisy. ( Sounds like a port cullis raising!) Raising the glass is assisted by some coiled spring devices which resemble steel tape measures.

That sounds very different to the 411 set up (as Sam said).

The 411 uses a screw inside a tube with a slot down one side. There's a bracket fixed to the screw which in turn is connected to the bottom of the window. (I'll post some pictures later from a different PC.) I'm sure it's not helped by the fact that the tube which carries screw is vertical but the motor is mounted horizontally, so the screw/tube has to bend through 90 degrees! But maybe they do that to stop water running down the tube into the motor!

Originally Posted by MYTA21

I have not taken anything apart yet, but the problem seems to be that on one window, the motor raises the galss to it closed position. For a couple of times, it will work up and down, never failing in an intermediate position. Then on closing, it fails to reopen-a click is heard.
Wind the screwdriver in the hole and it will work for a while.
So, am I correct in thinking this looks like limit switch?

That sounds like it is a limit switch issue. You could try Dick Smith or RS Components for something similar. When you do delve into the door can you take some photos and either post them here (or send them to me and I will post them for you - high resolution).

The limit switches on my 411 are fine, the problem is the motors operate very very slowly, but they're not noisy.

[Sam410]

Originally Posted by MYTA21

on one window, the motor raises the galss to it closed position. For a couple of times, it will work up and down, never failing in an intermediate position. Then on closing, it fails to reopen-a click is heard.
Wind the screwdriver in the hole and it will work for a while.
So, am I correct in thinking this looks like limit switch?

I had the same problem, but the other way around - the window would not shut from fully open. The bodies of the microswitches are made of an alloy metal of some sort which had broken up and collapsed (not for the first time it appeared, as it was already glued together with Araldite). These switches are handed left and right, and are unobtainable as far as I can see. As can be seen from the attached photos, I bodged it together with cable ties for a while, though I've now replaced it with a new switch, repositioned and with a new bracket made so that the window striker just acted correctly upon it.

Incidentally, I think these windows are unusual in having a limit switch at the top of their travel. Most windows do not have this, as can be determined by the slight dimming of headlights if you try to close the windows when they are already closed (at least on many modern cars I've tried.) As the problem on your 409 seems to be at the top, it would probably be possible to bypass the limit switch altogether, as the window frame will obviously stop the window going too far. Might be simpler than finding new microswitches?

[MYTA21]

Hello Kevin,
Has anyone come up with a solution for the replacement of the Piper mechanisms. My micro switches have broken up and I bought two second hand complete units from Bristol Services, but these are not up to much

[Kevin H]

Hi Mike,
I haven't heard of any replacement. Mine do still work, albeit slowly. I improved their performance by renewing all the wiring and connectors. However, if it's only the micro switches that are kaput, then I wouldn't think it would be too hard to adapt some modern micro switches to serve the same function. It would just be a matter of changing (re-fabricating) the mounting arrangement for the switches.

[Zorglub]

My "Series 6" 410 has a modern window lift mechanism that Bristol sourced from a U.S. company called Speciality Power Windows. It's very effective and look well built. Bristol also sourced a wiper motor mechanism from them for the series 6 that they adapted with a custom wheel.

Here's a picture of the power windows mechanism (I dont understand why the picture is upside down). The switches are standard, although Bristol added a small electronic module allowing for auto up and down.

[MYTA21]

Looks a useful answer. Trying to fix old type limit switches on not easy, Bristol Car Services have been looking for an answer, but no success to date Thanks

[Geoff Kingston]

Is it not a case that the limit switches are fitted to minimise injury if you or your child has an arm, hand of fingers out of the window when they are powering up. If they are playing up the system can be made to work without them all it requires to counter that retrograde mod is basic observation watch and listen and when the window is shut release the switch.
I have never had the doors apart on my 411 and despite 12 years plus off the road the windows work perfectly. On my 603 the drivers side works OK the passengers side not at all, it does not help that the wire colours do not match the wiring diagram, Greg Lowe however tells me the best way to get the passenger side working is to take the power feed direct as the way Bristol did it there is too much power drop off on the passengers side especially if the glass is a bit tight in the frame.
At the moment am struggling with the electric windows on a 1972 Rolls Royce Silver Shadow LWB and most of the problems are simply down to corroded connections on the wiring systems in the doors.
The 603 window motors by the way are off the series 3 Jaguar xj6 so at the moment are still not too difficult to find, not sure what's in the earlier cars though.