I have a 1992 XJS conv. The passenger side rear quarter window has stopped working. It was fine until a couple of days ago and then nothing. It won't go up. It went up without a problem and then back down as it is supposed to but nothing after that. The driver side still works fine. I checked the relays and they are fine so that leads me to believe it is the motor. I know it is a nightmare to get to but I don't know where to start. Any help would be appreciated.

 

This seems to be quite a common occurrence and it does seem that it is the right rear that is affected most. Do you have the workshop manual? The procedure is described there. It looks pretty straightforward, just lower the top then remove the rear quarter trim pad disconnect the motor plug and regulator and lift out the whole assembly. It probably sounds easier than it is

Just offhand though, you said the relays were good but did you test the voltages at the base or did you just swap relays with the left hand side? If you do not have 12V on pins 86 and 87 of the relay base then you might want to look at the thermal breakers.

Cheers,

Allan

 

Dear Jag, This worked for me, I hope it helps you. I had the same problem with my 91 conv. I posted the problem of removing the screw behind the window if it's stuck "up". If you've gotten past that problem then here's what I did. First after removing the panel to access the motor I popped out the plastic retainers that hold the motor cover (plastic), (leave the bottom retainer you can't access it) and peel back the plastic cover. You will see the motor and possibly the gear cover has popped off. This is because the RUBBER cushioning around the gear mechanism inside the motor has deteriorated and the pieces have been forced out such that they pop the cover off. I at first, thought that if I could fashion some pieces of rubber and put them in the spots that they were originally. That would essentially repair the motor, but I was wrong. These loose pieces eventually worked themselves out just as the original rubber did and jammed the motor once again. As I observed the motor with the space that was left with the dampening rubber gone I found that even though it was gone the motor still worked. The only difference was a 1 second delay before the motor engaged the gear due to the missing rubber. But the window went up and down just fine!!! Basically the system doesn't even need the dampening to work. I put the metal gear cover back on, (you must crimp the edges to hold it on firm as original). I popped the retainers back into the plastic cover and it's been working ever since. I forgot to mention... To unjam the motor at the start, You've got to run a pos and neg wire from the battery and power the motor directly (bypassing the window switch) switching the pos and neg wires back and forth which would jostle the motor back and forth in order to free the jam. This is what I did and now my motor works properly again. It's a lot of work but it beats the cost of paying someone else to do this chore. Just for safety sake, When I put the top down I stop just shy of putting the rear windows down all the way. So far so good. I hoped this helped some. That's what being part of this forum is all about. Bud

 

I was fiddling with getting everything removed and decided to try the old trick of tapping on the motor housing. Voila it started working again. I know there is probably an issue there but at least it works for now. Thanks for the help and I will use it to keep investigating. The help that you all give is what makes this site great.

 

Thanks for the write up Bud. Tapping the housing with a screwdriver worked for me as well, a few times.....
As I rarely put the top up in the summer, this can wait until the car is put away for the long cold winter.

Bill

 

Has anyone found a site that sells these xjs left rear window motors? I've tapped till I'm blue. Sometimes it works, sometimes not.

 

+1 on this.
In my 1990, both of mine failed within weeks of each other and although presenting as a non-working motor it was the disintegrated rubber damper in the "gearbox" jamming the worm gear.
As I remember (memory is a bit hazy), I completely dismantled the unit, removing the pinion that drives the register from the splined shaft which is a push fit but although loose afterwards was adequately held by using blue Loctite. I replaced the rubber with epoxy and made some looseness in it to give some freedom. I never thought about leaving it out altogether (that's inspired!) and I can see how that would work just fine, although the metal to hard plastic interface may be a bit damaging over time; just a thought.
Bottom line is that to properly check that its a motor issue you have to separate it from the gearbox and bench test it.
Getting the unit out is an exercise in 3D puzzle solving, getting it back in place is even more fun. good luck with it.

 

If it's a facelift car, you just go to Jaguar and buy one. They are still available. Is your dealer telling you that he can't get one?

Quarter Glass Regulators-Rear-Convertible - Parts For XJS from (V)179737 to (V)226645 | Jaguar Classic Parts UK

Paul

 

Has anyone had any success replacing the brushes on these rear quarter window motors? I have managed to clean up and recondition one of mine on my '94 VIN 188XXX, but the other side stubbornly refuses to work reliably on the bench even before I put it in the car. Seems to get stuck in certain position and wont move left or right, even though drawing a bit of current and producing a "hum". When I look at the brushes, one of them is worn a bit crooked and so the contact patch is probably only 1mm wide - perhaps the source of the problem? Anyway, was wondering if anyone had managed to find brushes to recondition the motor with? Or perhaps know a way to dress them?

Also, just so I check I understand, there is no drop in replacement for the motor (like the Bosch one for the front windows) - have to buy the whole assembly from Jag including regulator if available?

 

I've been having the right rear window problem in my 89 xjs. I'm not sure it's the motor though, I'm hoping for relay. Which relay is for the window? There are 6 back there and the drivers side works and I'd like to swap the relays to see if that's it.

It won't work for a few weeks, then it will work fine for a few days, then quit working again for a while. Usually won't work a lot longer than it will. But when it does work, it's fine. Doesn't seem slow or any problems like that. Just either working fine or not at all.

I tested the voltage going to the motor and it doesn't show any power going to the motor when it should be going up or down. I tested it on the wires going dire to the motor being the rear quarter trim. That's why I'm thinking maybe relay, but any thoughts would be appreciated.

 

Are both motors not working? If it's the relay that would happen. If it's just the common problem of the pass. rear only, then it's probably the "sticking gear" symptom. The electrical system in these cars can leave one baffled. When I first got mine the rear windows didn't work and ultimately found I had to rewire them to work properly. I shook my head and was just thankful I fixed the problem. So if you're not getting power properly It might not mean anything at all. I cherish the time I can just drive and not fix my xjs! Bud P.S. The working and not working problem is the motor being jostled by bumps into operational mode then it's jammed again when lowered. Then jostled again to work. If it's not working when the window is in the UP position then that's a whole different thing! Bud

 

I bought my 92 XJS in 2012, only had 40,000 MI and had sat for years in a garage (at least it wasn't in a barn under the proverbial tarp).
The left rr window acted just like yours. On our maiden voyage to San Diego I finally took it to a Jag mechanic there. He said that was a common problem and the o KY solution was to take the motor out and clean the isude, replace it, or real a steel rod down to it and tap it till it worked. Well, after doing that for a couple years, that didn't work anymore. I found Colorado's Jag Mechanic in Colorado Springs. When I told him what had been happening he just chuckled. He said that it was a common problem. And the only sure way to fix it was to replace the motor. He said the motors are in very short supply and the aftermarket Motors that say they fit do not. He looked all over the US and into Britain for one finally found one, put it in and I haven't had any problems since. I don't know if this was a leftover Lucas issue or not. If you want to get a hold of this mechanic, which I would suggest because everyone that I talk to and Colorado recommended him to me, he loves these cars and if you're not within range, or if he knows someone that can help you better than he, he'll gladly supply the name.Hiis name is Mark and he's at Concours Auto in Old Colorado Springs, 719 473 6288. It seems he has contacts throughout the US and Europe.

 

I outlined my solution here:

https://www.jaguarforums.com/forum/x...tached-162775/

Haven't had an issue since. It's my daily driver..

 

I agree that it is way more than likely that it is the bad motor problem so common to these and I'll probably be in there tearing it out soon. But before I dig in, I just want to be sure and thorough and checking the relay is an easy thing to do to make sure. However, I was under the impression that each window had its own relay. What you are saying is that 1 relay controls both windows, correct? My drivers side works, so if there's 1 relay for both windows, then its back into the side of the car for me.

The good and bad news is I had to rebuild the hydraulic ram a few weeks ago and had it completely removed and space in there. Of course the window was working then. And now everything is back together in there and its not. On the positive side, I know how to get in there and get that out of the way quick and easy now

 

A tooth to tooth and the motor jammed. As I understand it is also a common problem


I did not solve this problem. I just deleted the relay. And I ride with the windows raised

 

If you are one of the fortunate ones whose motor works when you smack it and the window goes up and down.........do this. Providing the motor is loosened and it's up already, when you lower the top as soon as the top bottoms out the window starts to lower, watch the window going down and let up on the switch BEFORE the window hits bottom, then it won't jam and will go back up every time. With a little practice you can get the top of the window to be even with the top of the side panel which looks as if it were all the way down anyway. Don;t take anything apart just watch the window. Works for me every time. Bud

 

I've been trying to rectify similar experience

Great picture of the armature and driven wheel mesh, to me it's getting overdriven , or made to work too hard.

It doesn't need to drive up & down with 30 kg to spare, I've fitted a limit switch for the left hand down and am considering a resistor or poly switch in the up.
full up mid point height adjustment and it'll grap with plenty onto a strip of a4 paper. Why would it need to be up any harder than to stop a whistle.

all weekend and no jam down on the left or right yet

 

For the electrics look here 1989
https://www.jaguarclassicparts.com/uk/parts-news

 

Gidday folks

now > 8 months and ~3 months for the Rh down and it hasn't jammed either, this since I fitted limit switches in the down travel.

about 6 hrs a side to access, measure, make switch mounts, fit & wire in series with the down relay winding. still got to put the plastic covers back in , a warm day exercise.

 

IMG_20180322_102338.jpg


picture of the switch & mounting.
100% reliable sofar.

Kind regards Donald