1990 XJS Convertible, hot wire the rear windows?


My friends 1990 convertible top has not been up for several years, the pump reservoir is virtually empty (shot), hydrolic cylinders shafts are badly rusted (shot) The rear windows are not lowering as needed to remove rhe quarter panels top outer screw behind the glass!!!

Any idea how to lower the windows? I have power to the 30 amp fuse which blows when the console switch is held down. Must I destroy the rear panels? I fear the window mechanism may be seized or rough adding stress to the electrics.

Ideas are welcome and appreciated.
Anybody have a pair of tan quarter panelsfir sale?


Pull the LEFT quarter DOWN relay and ‘jump’ 3/5 terminals. (30/87)
Pull the RIGHT quarter DOWN relay and ‘jump’ 3/5 terminals. (30/87)

Leave the UP relays alone as they complete the ‘earth’ circuit to power the window motors.

See circuit diagram 29.1 of the electrical guide S57_90 .pdf. (same as 1991MY)

Thanks Motorcar man.
I “tested” all the relays with my “Relay Buddy 193” and oddly, all 6 failed. So I tested them with a battery pack and they all click good. ES will be gettin a call from an uhappy customer.

Before I try to run them down again, i will get the owner over here to assist the windows down. While my wife pushes the down switch, we can push both windows downward and hopefully the fuse will not blow. If I can get the quatrer panels off i can get some lubrication where needed…

Still waiting to gear back from the owner. Will update if it works.

I have successfully removed those screws next to the rear window glass using a Pozidriv #2 bit held in the teeth of a pair of vise grip pliers. It is slow going, but the screw threads are coarse so not much time is needed to remove each screw once it starts to move.

Once you get the rear panels off you may be able to raise or lower the rear windows by applying power directly to the motor wires. I use a small battery jumper unit and alternate the + and - wires to the motor red and green wires to raise or lower the windows. This may work, but if the motor has failed or if the track is stuck you may need to remove the motor and regulator to get the window down. I just went through this with my 1990 XJ-S convertible parts car.


Thank Paul,

My plan WORKED! Two men pushing the windows down while my wife worked the switch!!!
I am lubing everything I can see that moves the glass and then some. All new parts will be here to refresh the lifting system with the new black top.
Its all down hill now until the next crisis.

Well the learning continues. Lubricating in place did nothing, the ei dows will not go up. So, dismantle, clean and lube during reassembly.

What a mess.

Did you bench test the motors and the actuarors after reassembly to make sure the motor and actuator works in both directions, limit to limit?

If anything is binding, it will be easier to see on the bench.

Hi Jerry,

I removed the left rear motor and actuator and its a miracle I got it to roll down. It does not work on the bench. I will try to remove the motorto test off the actistor.
I will probavly now be looking for both rear and a right front motors.
If anybody has them available, please reach out.

Thanks for the help.

I would remove the motor from the actuator mechanism and test it. If needed, you may need to rebuild it (at least take it apart, clean the shaft ends and bushings, then (as best possible) try to get as much oil into the bushings as possible (about the only thing you can do with oil impregnated bronze bushings may be to let them just soak in light machine oil, I doubt there is a practical way to actually “re-impregnate” them with oil).

While the bushings are soaking, turn your attention to the actuator mechanism. You may be able to operate them with a cordless drill attached as possible to work then while cleaning and lubricating them.

That may save you from having to try to find replacement parts.

I tried to remove the motor, but I could not move the gears to access the third bolt with 12volts or manually turning the small gear. I may be able to cut a socket sized hole in the half round gear without really damaging it to reach that bolt. Its woryhkess as ig is anyway. I may try that.

If it’s similar to the one in the photo @Paul_M_Novak provided, can you remove the bolts that hold the motor to the reduction gear housing?

Hi Jerry,
Sorry, I had to make a mad 1,400 dash to Canada and back in two days.

Hi Jerry
I just returned from a 2 day 1,400 mile drive to Canada from Southern Oregon.
Yes, before leaving, I did just that and the motor looks pristine. Nothing out of order or dirty and well lubricated on the top bushing. So, it looks like the actuator is probably the issue.

Ok , after lifting the armeteur out EVERYTHING moves freely and easily so I could remove the 3rd motor bolt. Do these brushes look like they are shot? Anybody know where to get new brushes for these motors? The armeteur turns perfectly, well lubricated.

I found new brushes. 4x4x10mm with a copper strand to solder onto the cut off original.
If I am careful. Should have as good as new motors.


I was going to say those brushes are shot, good you have found replacements.