I have a 1990 XJS convertible that the rear quarter windows will not go up after top is raised. Just wondering if anyone has bypassed the relays and hard wired the windows to a switch. Thanks, DJ

 

Welcome to the forum Davey Jones,

I've moved your question from General Tech Help to XJS forum. Members here with the same model will be able to help.

Graham

 

There are a few threads already about this problem. It seems it could be a problem more with the motor than the electrics. Heres 1 of them....


https://www.jaguarforums.com/forum/x...-motor-103207/

 

Yes, Davey Jones. I did disconnect the top computer module, located just in front of the relays, and wired the relays directly. This is accomplished by going to the relays in the boot and finding the wire that is supplied with 12V by the module when you lower or raise the top. Soldering the new wire to the old wire at 'top up and top down' relays. You can just pinch the new wire under the spade contacts but soldering is better. I drilled a hole in the bulkhead just above the top relays and pump. Running the wires under the bask seat and under the console at the rear and to a toggle switch just in front of the left window switch. Now I can lower the quarter windows at will and also the top whenever I want without having to be in park or with park brake applied.

I know this eliminates safety features so I won't raise the top at speed on the road but I do not believe anyone would do that anyway.
Cheers, RagJag

 

I think you can do that with out removing the top computer module,

all the relay coils are supplied with 12v... add another wire to each of the relays coil that head to the computer module that you want to manually activate to a window toggle switch one switch for two relays (up and down) and the common to ground... wa la a manual override...

just two more window switches or a toggle to make the two front window switch do double duty... one way for front and toggle it the other way for the rear quarters...

I have spent too much time looking at that circuit.....


all my windows are now working... no mods...

still I might want to raise and lower the rear 1/4s with out having to tie down the top...

you know put the boot cover on it and the try to close the roof so you get the 1/4s up...
( I like the 1/4s up with the windows up and the top down...)

 

You are correct, Johnathan. It is not necessary to remove the top module. I didn't remove it. I just unplugged it. This was so I could lower the top without having to be in park or have the parking brake set. I only had to install one extra toggle switch for the side windows. My front windows work with the original switches. I also drive with the top down and all windows up.
Simply a way to eliminate a spot of possible trouble. Not the only way, I am sure. It works for me. We both are violating purist protocol, of course. lol
Cheers, RagJag

 

ah,
remember... there is a delay on the up of the windows when putting the roof up.

If you have the top up and locked in place and hit the down for the top the 1/4s drop right away, then when you push top up you have to hold it and make the top pump groan then the 1/4s will rise after a delay 8 to 10 seconds

when working on the 1/4s I pull the fuse on the top on the pump

 

Yes, I know all the process it goes through. I can determine no reason why the 1/4 windows have to be delayed. Mine go up and down independently of the top's position and seem to have no problem doing so. Unplugging the module eliminates all that.

Jaguar is an interesting car simply because it does have eccentricities found on no other, such as the park brake handle position. I am tempted to move that to the right of the driver but it would be a considerable trouble to do so.
RagJag

 

I believe I have both rear quarter panel window motors that I removed from a parts car. If you need one or both, let me know and I will sort through the garage to find them and bench test.
Ken in Charleston WV