'tis a Jaguar.......they do that sort of ****....

 

I recently had a similar problem with my '89. One day I put the top down and both rear windows went down normally. But when I put the top back up the passenger side rear window would not go back up. I cycled the top many times but the window refused to go up.

I removed the panel and put 12 volts directly to the motor...no go. So I pulled the motor out and took it apart.

What I found was a lot of carbon build-up on the commutator. I cleaned the commutator with a brass brush, cleaned the brushes with electrical cleaner, re-greased the output shaft and put the whole thing back together. Applied 12 volts and it ran perfectly.

Reinstalled into the car, operated the top and the window now works fine. I suspect that the carbon created a dead spot preventing the motor from operating.

I plan to eventually remove all of the other electric motors and give them a similar clean-up.

Mark

 

theory of operation of the top and rear windows....
upon inspection of the circuit you will notice that

the base state of the system is that
ALL motor wires are GROUNDED

the ecu upon checking that all conditions are meet
a) key on
a) park or neutral selected
a) parking break on
then allows input from the roof switch

which then grounds the appropriate relays

when relay is grounded its switch from providing a ground path to supplying a supply Current...

if the fuse is good and you have tried swapping the middle two relays
(they are for the top) and you still do not have movement in the top
then you may have a hydraulic problem...

if you are raising the top manually and you do not have enough Hydraulic fluid it will draw as much up as it could until it starts drawing air...

in the down it just sucks the hydraulic fluid out then what ever air it can...

check your fluid level

I hope that you have not damaged your pump in the mean time...

newbie at large
Jonathan

one of my windows is giving me trouble...
that is why I have the whole of the thing in my head...

 

Hi, my top on my '94 XJE is erratic. Sometimes it workd, sometimes not, same with the rear windows. The fluid reservoir is less than half full. Don't know how much should be in there but less than half doesn't sound right. If I'm reading correctly I need something called Univis J13 which I haven't been able to locate. Anybody know what I can top it off with without draining and starting over?
Thanks

 

If the windows also don't work sometimes, then it doesn't sound like a fluid problem as the windows are not dependent on the hood working. I would go back to basics and check the hood switch is clean. If the hood switch is sound, then my first suggestion is look at the handbrake switch which is the biggest single cause of the hood not operating.

Good luck

Paul

 

Thanks,
Any idea what fluid I can use to top off? For that matter how much should the reservoir hold? Its well under half full but no obvious leaks

 

A bit of cross-fertilization here; from britishcarforum.com:

"The Jaguar XJ-S Repair Operation Manual in Supplement C for 1988 1/2 - cars calls for use of Univis J13 Hydraulic Fluid.

Univis J13 is a petroleum based hydraulic fluid that was made by EXXON, but no longer is available, although EXXON does have other fluids called UNIVIS listed on their website. The site information on the two Univis fluids listed did not indicate if either met Univis J13. It is currently available as a Texaco Aviation Hydraulic Fluid according to a websearch for Univis J13. I went to a local aviation parts supplier Falcon Crest Aviation Supply based in Houston, TX (713)644-2290. They were able to cross reference the Texaco Hydraulic Fluid that met Univis J13 to MIL-H-5606A.

There are several manufacturers of aviation hydraulic fluid that meets that MIL number. Falcon Crest Aviation Hydraulic Oil 15 is listed as the equivalent of Aeroshell or ROYCO 756E, which is MIL-H-5606A. I bought a quart can of the Falcon Crest Hydraulic Oil 15 for $6.01. The color and smell are the same as what is in the reservoir on the pump."

A word of caution, the level being below the centre possibly indicates a leak through the motor shaft seal. You will find out in a couple of days by looking on the floor (ask how i know). Fix is covered elsewhere on this forum. Good luck!
graham

 

I have a spare pump and relay assembly from a 89 if anyone needs it.

 

About fluid. Already 20 years using conventional ATF