408 power window wiring problems
 

I'm currently working on a 408 and I'm trying to get the Piper electric windows working. The wiring is in a bad way and needs replacing but I need to get a wiring diagram for the window lift system. The diagram in the workshop manual unfortunately doesn't include electric windows. I've got a diagram for a Bentley of the era that uses the same system, I believe, but that doesn't include the windows either! Can anyone help?

Also, the wire passing through the A pillars is very flexible (steel?) multistrand for obvious reasons. I've been unable to find anything similar. Any ideas what I can replace it with?

Thanks for any help.
Mark

Mark,
Have a look at this there is a wiring diagram on page 12.
Geoff.

https://rrtechnical.info/sc/sc1/wshop/17.pdf

Thanks for that Geoff. Unfortunately the motors shown are different from those on my car (no solenoids, for example) and the wiring is rather different by the look of it. In fact it was a 67 Rolls I worked on that definitely had the same system as mine so I'll see if I can track down a diagram for that. I just assumed that an earlier car would be the same.

Thanks again
Mark

Mark,
I assumed being a 408 that it might have been S3/SC3 but obviously not, some Jensen's had piper motors as well but finding a wiring diagram is probably equally difficult. I have never been able to get the passengers door window to work from the switches but a few months ago having effectively hot wired the seat controls on a range rover classic using more modern and simple 6 pin window switches I intend all going according to plan to rewire the passengers door window motor to operate independently from a new switch in that door, if the 408 is wired the same as a Silver Shadow its far too complicated when it gets old, though I am sure there are some around who understand the electrics of it perfectly. Sorry can't be of more help.
Geoff.

If only Bristol's workshop manuals were as good as that!

I find it astonishing that they left the electric windows off the wiring diagram yet included the wiring for many more simple components.

Mark, as an aside, does your workshop manual have pages 24 and 26 in the electrical section?

Are the window lift switches on the 408 on the doors? Is there a switch for both the passenger and the driver to operate the passenger window?

I ask because if there is both a passenger and driver's door switch for the passenger window, it's likley that the passenger door switch is reliant on the driver's door switch being wired correctly.

In case it is any help here's the wiring diagrams for the 411 - see pages 12 & 13 for electric window wiring. Many things remained the same from one model to the next on Bristols!
.

Mark,
My understanding is that electric windows were only introduced into production with the 411 S2.
But probably quite a few of the earlier cars like yours could have been retro fitted with electric windows by BCL or any Auto electrician or home mechanic .

Geoff

Quick update. I've got the driver's side done and working. Once you know how the Piper mechanism operates you can work out how the wiring should be done. I had to replace much of the wiring but at least I understand it and should be able to sort the other side too. Unfortunately, none of the diagrams mentioned by others matched my system but luckily it's not too complicated to sort out.

Thanks for your help.
Mark