Last week my convertable top on my '94 XJS stopped working. I put it up and that was it. Motor doesn't run up or down. The fuse is ok, I tried moving to a power window switch, and the break light comes on. Any ideas before I give up?
Thanks

 

If you read the workshop manual you'll understand the circuitry and realise that there are separate relay-controlled circuits for the rear windows and hood.

It's extremely unlikely that all the relays failed at exactly the same time, so if you know the hood switch is ok (the brake light is not linked in any way to the hood circuit, by the way) and the windows don't go down either, then the problem almost definitely lies in one of the 2 other inputs going to the ecu. These are the gear selector switch (must be in Park or Neutral) and the handbrake switch which must make contact.

My money would be on the handbrake switch not having made contact.

Good luck

Paul

 

How do I check the hand break? The dash light comes on.
Thanks

 

I agree with ptjs1
Buy yourself a digital volt ohm meter, if you don't own one, and get a copy of the wiring diagram. I think you're going to have to trace voltage to find out where the break is and the DVOM is the best tool for that.

 

Now you arae getting over my head. Any way to bypass the parking break mechanism?

 

acbsfb,

Yes you could bridge the switch but if checking the continuity is above you, then that would also be difficult. As a suggestion,

- make sure you're using a known switch (working window switch)
- pull on handbrake. Now pull one more notch!
- put transmission in Park
- Try hood down
- If no joy, put transmission in Neutral
- Try hood down

If still no joy, then you will need to check that the transmission switch and handbrake switch are sending their signal to the hood ecu. You can do this by connecting a meter to the back of the correct hood ecu pins.

As mentioned, read the service manual section and look at the wiring diagram and you'll understand the process and the pinout of the ecu. At the risk of possibly sounding critical, don't think about trying to run an XJS cost-effectively without owning the correct Jaguar parts & service manual.

Good luck

Paul

 

"don't think about trying to run an XJS cost-effectively without owning the correct Jaguar parts & service manual."


Paul really nailed it with this comment. You can't own an XJS on the cheap both financially and depth of knowledge. You may not need to be an expert but you really need to be knowledgeable; "an educated consumer". The XJS is a complex luxury car but the engineering is straight forward. Don't try to shortcut the process, otherwise you'll end up with a s**tbox pushed into the back yard.

 

Thanks, I've already tried the power window switch on the top as well as trying in both park and neutral. Any idea where the transmission and parking break switches are located?

 

Also, is there a manual I can download?
Thanks again

 

The best documentation available is the service DVD from any Jaguar parts supplier for about $75.00

 

I paid 18.00 us

Jaguar XJS XJ s V12 Service Parts Manuals on CD for 5 3 and 6 0 Liter | eBay

 

acbsfb,

Be careful if you don't buy the new genuine Jaguar DVD. That ebay link is advertising JHM1176 which is the old Jaguar CD-Rom for the 6 litre XJS. It doesn't cover the 5.3 or 4.0, although some of the parts and mechanics are the same. The old Jaguar CD-Roms also don't work properly on a Mac whilst the new DVD does.

Just be careful in your choice.

Paul

 

Just a thought, but you can easily take the switch out and clean it up. Mine was not working because of the carbon on the contacts. I cleaned it, the top works great!