Window lift motor replacement?

[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.

[MYTA21]

Thanks, Yes, I was thinking of " listen carefully" option! I've had no luck with alternative limit switches, but made two up out of the four spares from s'h lifters. Getting the tension in the chain etc is important as thethe unit can run on bit after power is cut. Now going to have another try, with out the switches.
I have seen some complete kits for sales at reasonable prices. Some use the original square shaft of the manual winders, but some "hot rodder" options look to be a stand alone fitting. Will update with any success.

[MYTA21]

Hello,
Having struggled on with the old Piper motors on the 409, I finally decided enough was enough! Limit switches unobtainable and a couple of s/h units from Bristol Services saw me override the limit switches. However, the noise and worn out chains became too much.

I searched for alternatives here in Australia and the best solution I could find was by looking on Ebay where I sourced a kit designed for hot rods! For A$400 I got a pair of motors, mechanisms and looms with switches. These work like a wiper motor rack system and there's a need to cut the mechanism to fit. It would appear that I can retain the weight assistors fitted in the Piper set up, plus leave the metal channels at the glass bottom, plus guides in place.

If anyone is interested, I will provide photos. Issue may be with getting the wiring installed, but all harness is supplied.