1990 Jaguar XJS V12 Convertible.
I would like to convert the rear quarter glass panel to manual operation, I saw a posting on the old site but I cannot enlarge the pictures. Where I live it is very hard to find a good Jaguar mechanic and I want to attempt this myself. I have the tools and mechanical knowledge but not electrical,
Can I get some help in reviewing the pictures or description how do it?
Thank you
Quinto Rapacioli
1990 Jaguar XJS Convertible
By âmanual operationâ, do you mean you want the windows to be operated independently from the top? Or do you want to replace the motor with a hand crank?
I would like to add 2 switches to operate them at will since now is a hit and miss operation
Since they are hit or miss, if like to remind that the #1 reason for a miss is that the roof open /close cycle was inadvertently reset half way through the operation. If you momentarily and slightly release the hood switch with the roof half up, the rear windows will not go back up until youâve depressed the button continuously for a complete standard cycle duration⌠basically Iâm saying hold that roof button down even after the roof is all the way up (it will make noise, donât worry!) and eventually itâll put the rear windows up. This is harmless and noted in the manual.
Quinto,
In 2007 I first posted about my conversion of the rear windows in my wifeâs 1990 XJ-S convertible from automatic control to manual control through the use of two XJ6 window switches that I located at the rear of the console. I believe that the original automatic convertible top/rear window design implemented by Jaguar was too complex and unreliable for long term use. It required two thermal breakers, six relays, three switches, three electric motors, and a ECM to properly sequence the convertible top and rear windows. What could possibly go wrong with that? 
After two years of ownership and numerous instances of either one or both rear windows not going up or down together as they were supposed to I was fed up. I disassembled the motors and cleaned them, tested all the relays, and adjusted everything that I could, but still we ended up with either one or both rear windows not going up or down when they were supposed to. The recommendation that Jaguar had when this happened was to recycle the top either up or down to get the windows to behave properly. Of course that didnât fix anything, looked embarrassing, and so I decided to simplify it with switches that would allow manual control of the rear window either together or separately.
It has been 13 years since I made this modification and it works as perfectly today as it did when I made it. We live in the San Diego, CA area and use the convertible top all year long. The rear windows always go up and down when we want them to, and not when they decide to. This modification doesnât help to raise or lower the windows if one or both of your rear window motors have failed. It just bypasses all the automatic features of the rear windows when you operate the convertible top, and you simply raise and lower the rear windows with the new switches that are powered by the wiring for the door windows.
I sold about a dozen kits of window switches and connectors from my three Series III XJ6 parts cars to others so that they could make this modification themselves and I have answered questions from several others about the modification when they wanted to make the modification using their own switches and connectors. Those that have made this modification have all been pleased with how it works, but some have had to replace window motors in order to get it to work because their window motors were no longer functional.
I recently sold two kits of switches, connectors and wiring diagrams. I donât know if I have any more connectors left from my parts cars, but I can look and see if I do. One recent kit went to someone with a facelift (1994?) convertible and he put the switches inside the center console arm rest. So not everyone installed the switches where I did.
If you are interested in more information please send me a Private Message [PM] letting me know what you need and I will do what I can to assist. My original post on the old Jag-Lovers-org website is still active and the descriptions in the pictures provide a lot of helpful information about making the modification. However the pictures no longer provide the detail that they once did, and I am not sure what can be done about that. I no longer have the pictures that I took when I made the modification.
Here is the link: http://www.jag-lovers.org/snaps/snap_view.php3?id=1174156649
Paul
Itâs interesting to hear of different peopleâs experiences with the XJS convertible top & rear quarter windows - Iâve had my 93 6.0 2+2 convertible for almost 15 years. I have replaced 1 blue top relay & other than that, I think there have been 2 occasions when the rear quarter windows werenât where I expected them to be & both of these were easily rectified. I actually like the idea of pushing buttons to lower the rear quarter windows independently of the convertible top & creating a pillarless coupe after also lowering the front windows.
Rgds.
Andy.
Andy,
There was clear evidence to me that the rear windows had been worked on before we purchased the car as some of the panels or cover fasteners were broken, missing, or installed improperly the first time I took everything apart. I remember thinking âhmmm, someone has been in before and left a bit of a mess.â
Paul
The link isnât helping much. Apparently the photos were not transferred. I get them in their small configuration but they wonât enlarge.
Stephen,
Yes, that is correct. For some reason unknown to me the pictures that I posted on the old Jag-Lovers site did not make it over to the new site properly. However, I provided a detailed description for each picture that gives all the info necessary to do the modification.
Paul
Paul,
At the time I replaced the blue top relay, I removed the rear seat base, the appropriate Side panel & the quarter window motor. The ârubber spiderâ appeared to have forced the galvanised cover plate off the motor housing. I put the motor back without the plate about 13 years ago & it has worked fine ever since - the car lives in a garage thatâs integral to our house is never intentionally driven in rain or on salt treated roads.
Rgds.
Andy.
The reason is lack of resources and the subject has ben covered many times.
There is a workaround to display the images properly, courtesy of Paul Korbes:
Andy, the Ford-ifed Jaguars typically suffer from fewer electrical gremlins. Many of us never experience the same problems reported for the pre facelift cars.
Hi Andy, On my 95 you can open the rear windows with the roof closed by simply holding the roof down button with the roof latched. After some whirring noise and a delay the rear windows will go down. No mod needed. -John
John,
Interesting info.
With my modification you can open or close either or both rear windows with the top up or the top down. My wife really enjoys driving with the convertible top down and sometimes when it is cool out she will drive with the convertible top down, all four windows up and the heat on. This gives her the open air motoring that she enjoys very much but with a heated cabin. We have also taken her convertible to drive-in movies on cool evenings with the convertible top down and raised all four windows to block the breeze. Since we live in an area where it is convertible weather all year long, this modification gives us a great deal of flexibility on how to use the rear windows almost every day of the year.
Paul
Thank you for responding
My windows are stuck in the up position. I try both way what you suggested but it did not work.
Thank you all for trying to help.
The windows are stuck in the up positions.
Today I removed the panel on the right side I disconnected 2 wires to the motor and applied power to one at a time using the Power Probe III but I did not get and movement. Maybe the motor is defective. TI was trying to get help on the procedure of applying power to which wire and to test the motor.
Paul do you remember what wire you applied the power? I did not see a ground wire, I tried to add the ground from the relay socket but nothing.
Quinto,
You need to apply power to both wires at the motor to get it to work. If you apply +12V on one wire and -12V on the second wire the motor should move in one direction. If you swap the wires around the motor should move in the opposite direction. If you try this and the motor doesnât work at first, try swapping the wires because you might be moving the window up and it is already up.
If the first side motor doesnât work try the other side motor. If it has been a long time since the motors have been used they might take a while to get moving. Take notes and pictures as you go along so that you can always return everything to how it was when you began.
Write back with your results.
Paul
Quinto . . .
Several years ago I had this problem with my 1990 XJ-S. The quarter windows would work fine for 3 or 4 up-down cycles of the roof, then the right side one would stop. Fortunately it always stuck in the down position - the up position would have been more of a problem, since the glass prevents access to the top screw that fastens the upholstery panel.
I became quite adept at removing the upholstery, removing the metal plate covering the motor, and giving the motor a couple of good hits with a hammer. This would result in the motor working again for another 3 or 4 cycles. By the way, I left that top screw off after a few repeats of this procedure.
Finally, I managed to get a replacement motor from a Jaguar recycler. Installed the motor and have not had any problems since.
. . . Ron
I recently studied window motors; I would have posted my findings, but got hung up trying to figure out how this new site works and never got back to it.
I can tell you, though, that both the Delco motors in the earlier convertibles and the Bosch motors in the later ones are remarkably similar in configuration, and both use a 14-tooth pinion. The regulator also appears virtually identical. Itâs entirely possible the only significant difference is the location of the mounting holes for the motor. The Delco motors are junk, though, while the Bosch motors are far more reliable. So, if the Delco gives up the ghost, it might be a plan to replace it with a Bosch motor, possibly requiring elongating the mounting holes or drilling new holes. A Bosch motor from a Mercedes W123 should drop right in. A Bosch motor from several other cars would work if you can swap out the pinion gear.