Hello all.
Just bought the car last November and first time trying to get the top to work
95 XJS 4.0L

Can someone please confirm that the two rear quarter windows are supposed to go down in first sequence of operation when you press the top down switch?
Also, I know there must have been a leak in the pump or reservoir because it is empty of fluid. When depressing top down button, I can hear the pump operating but of course no movement of the top as expected with no fluid.
Question: Should the rear windows still go down even if top operation is selected to manual? If electric does not work, how do the rear windows go down prior to bringing the top down by hand (with hyd override selector enabled). What is the proper operation to get both windows down and then fold down the top by hand.

Thanks,

 

I can confirm that yes, the quarter windows go down immediately when I press the roof down button. Of course the transmission must be in Park and the emergency brake must be on.

I can also confirm that even when the roof is in manual mode, the windows still rely on the roof switch in the car. Same theory, car must be in Park and emergency brake applied. Remember that on the way back up, the quarter windows wait about 10 seconds before going back up. That delay happens with or without the roof in manual mode.

If power is out altogether to that switch, you won’t be able to move those quarter windows, however there is a way to add a new switch that can actuate only the quarter windows. If you do a search of the forum you’ll find that wiring diagram.

 

Thank you for that.
To review putting the top down in manual; do I depress the down switch first to bring the windows down and then unlatch the roof handles to bring the roof down by hand?
In my case, even though I do hear the pump running when I depress the down switch, the rear windows do not go down. I do have trans in park and park brake applied.
If I do hear the pump running, that would mean I should have all the conditions met, correct? At that point, why would the windows not go down?

I guess I could try jumping the rear window relays to see if the windows work independently from the roof switch.

Thanks,

 

 

...except the rear quarters do not go down when roof switch is operated. All conditions have been met prior to roof switch operation. Door windows down, in Park, park brake pulled. Strange that both rear quarters do not go down.

Will have to see if I can operate the rears independently through their respective relays.

 

Manual raise roof and latch then raise windows. My passenger rear window stays in up position, left goes up and down.

 

macdoesit,

You have a stuck motor. If you ever want to fix it, you can pull it out, take it apart, clean it up, and it'll work for awhile.

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

It's been working great ever since. I spent $0.

carsnplanes,

It's gotta be a dead fuse or relay. No way they are both stuck at the same time. The fact that you can hear the pump operating means the switch itself works.
The pump has all the relays you need. There should be six relays. The left two control the left quarterglass (up and down) and the right two control the (drum roll please) right quarterglass. The middle two controlling the top.

 

Thanks Vee,
I thought I looked at the wiring diagram and see that the power for the windows is the same for the roof control/pump. If so, as long as I hear the pump with the roof switch, there should be power to the windows, so I'm not sure about the "fuse" you have stated. There is what I assume to be the main fuse for the conv top sitting next to the relays (30 amp). Should this not be the main power source for the windows too?
Diagram shows roof control to provide a ground to the control module when switch is depressed in up or down position. Depending on the switch position (Up or down), module outputs a ground to the respective up or down relays for each window. Power for the relays come from the switched ignition and are waiting at each relay though the thermal fuses. I don't remember seeing a fuse between the Ign and the relays except for the thermal fuses. Next, I'll need to check input power to the relays....or check output ground from the module when switch is activated. Also, I can't see more than one relay being dead...but stranger things have happened before.
Thanks for your reply.

 

The problem is the power grounds through the opposite relay. So there is power supplied through one relay and grounds through the 87A contacts of the other. They do wear out over time and the contacts get burnt.

Replace them with 40 amp relays with the centre 87a terminal and it should work again. Standard auto relays are 30amp supply and 20 amp rating on the 87A, it's the 20 amp rating that is the problem. A 40/30 Amp cures it.

 

I think I may go the route of adding switches to independently raise and lower the rears. To do this, I would break into both ground input lines from the roof ECU module to the relays. In "normal" position, the switch would provide the normal ground path from the module to the relays. In "Override", the switch would provide another ground path which would provide the needed ground for the relay to pull. Is this what others have done?

 

If you search, you'll find threads like these where people have taken control of those rear windows:

https://www.jaguarforums.com/forum/x...relays-138077/

I know there's at least one other person who added a switch where the rear AC grill is, just behind the arm rest.

 

Thanks Vee

 

Just a follow up question on the rear windows; are they electric in operation or hydraulic?, meaning is there a hydraulic pump or motor where the windows are hydraulically linked to the top operation? I thought I read something about somebody fixing the hydraulic portion of the system (topping the reservoir up) and suddenly the rear windows work. Did I misread something?. I know they work with the top using the electric switch, but is the up and down motion of the windows using hyd actuators rather than electric mechanical motors same as the door windows?

Thanks,

 

Windows are electric.

 

ok, thanks!

 

Hello to all,
hopefully somebody can help me resolve a problem that I have, after I did some work on the top pump. The top of my 1992 xjs had stopped working so I checked the hydraulics in the back. Found a leaking pump and 1 leaking cylinder, no fluid left in the reservoir. Bought 2 new cylinder, oil seal for the pump and 1 liter of fluid. Took many pictures of the existing set up to make sure I would re-install correctly. Replaced the parts and the top started working again, BUT... now it works in reverse. When I push the "down" button the top goes up and when I push the up button it goes down. The problem is that when the top goes up the quarter windows go down, when the top goes down the windows go up. This is a big issue because at night I have these windows open.
I checked many times and all connections are as they were before. It seems to be an electrical issue but all male/female jacks I had disconnected can only go back in one position, you cannot plug in these wrong.
Any suggestion would be really appreciated.
Corrado

 

I would simply swap the supply and return oil lines at the pump, that will get everything working in sync again. You might need to raise and lower it a few times to work the air out after opening up the lines.

 

Follow up to my original post. Having some time to look into why my quarters don't go down when the top down switch is selected, I spent some time following the electrical schematic and trying to work the both windows with just power and ground separate from the switch circuit. What I should have done first, and I will remember the next time, is to start with doing a quick continuity check of the window motor itself, leaving out all the up, down and relay operation until after. What I found was that both motors were "open" when taking the measurement from the relay socket. This meant that either both motors were burnt out or both were not connected somewhere. What I was trying to avoid all along was to remove the rear side panels to inspect the motors. Had I done so first, I would have seen both motor's plugs were disconnected, for whatever reason. This is what one finds when buying a used car. You just don't know what the reasons are for previous work done. Once I hooked up both window plugs, they both worked. Immediate down operation and delayed up action. Currently I have the top in hydraulic override until I can reseal the pump as it has lost its fluid and i'm sure its the pump that's leaking . There's oil residue on the tray under the pump and motor.
So there you go. So, always check to see if the motor yo uare troubleshooting is hooked up electrically either visually or electrically before going any further.
Cheers