I've decided that I'm going to give this a try now. With a measured .1v in my car on the odd circuits, I'm hoping that even an LED with its reduced current draw won't illuminate on the Sport circuit etc. when not required.

I think I've found a source of white, red, blue, grreen and yellow LEDs with the following spec:

Base: T5 B8.5D
Operating Voltage: 12V
Light Chip: Super bright 5050SMD(3 Chips)
LED Quantity: 1pcs
Brightness Efficiency: 16 LM
Lifespan: 50,000 Hour

They are only £0.54 each here in the UK. The ones from superbrightleds may be better quality(?) (although lower lumen rating) but I've heard they charge $100 for a set. That sounds an incredibly high price compared to the ones I've found, so I'll give mine a try.

Will report back in a week when mine are delivered and I've fitted them.

Paul

 

I was thinking of putting the relay in series with the transistor, using the emitter to switch the relay on and off.

 

I see what you're saying now.That might work.

 

All,


Update on the transistor in the "Sport" mode LED circuit.


I pulled my cluster today and replaced the flexible circuit board (original had some torn copper contacts at the bulb/led sockets). That all went well, and was fairly easy to accomplish.


I had intended to clip the transistor out of the circuit on the Sport mode led, and see if the signal was sufficient to drive the LED directly. I had been assuming that a positive voltage was applied to the base of the transistor to turn it on when Sport mode is selected.


But, before trying that, I measure the voltages on the contacts leading to that circuit. It turns out that there is a constant +12VDC being applied to the base of the transistor when the ignition switch is turned on.


When SPORT mode is selected with the center console switch, the voltage being applied to the base of the transistor drops to 0. It seems that positive voltage to the base of this transistor keeps it turned OFF (except for some apparent leakage), and when the voltage is removed, the transistor will then pass current, which then lights the lamp/led.


That explains why they needed a transistor in the first place. +12 volts is present all the time until Sport mode is selected. Then it turns to 0 volts. So the transistor was needed to "Reverse" that in order to light the lamp when Sport mode is selected.


So, I can't think of a way to eliminate the transistor from the circuit. The new circuit board exhibited the same problem...Sport mode lamp glowing all the time. So, I put a regular lamp back in that one position.


-Greg

 

Greg,

Tks for that. A couple of questions if you don't mind:

- Does the transistor on the 1st gear lockout lamp function in the same manner?

- What voltage leakage do you have to the bulb when Sport is not selected? Is it as low as the .1v that I have?

I'm going to order my bulbs this week and at present, I'm going to order enough to do the Sport, 1st lockout & MIL bulbs as well.

Tks

Paul

 

Paul,
I can't say for sure what your 1st gear lock-out circuit is doing, because my circuit board is different. Since SoutherGypsy seemed to have some interaction between the Sport Mode and 1st Gear lock out lamp, they may be linked together in some sort of push-me-pull-you/flip-flop fashion.


I think your circuit board is going to be more like SouthernGypsy's than mine. I looked again at the picture of the back of his cluster (posted early in this thread), and the contact traces are different at the bulbs, and the bulb color sequence is very different too.


I didn't measure the voltage or current coming to the bulb when sport mode was not selected. I only measured at the harness connector pins to ground, with the cluster removed.


Sorry I couldn't offer more info on this part of the issue.


Thanks,
Greg

 

I bought the LEDs recommended by SouthernGypsy (thank you!) and thought I could install them myself on my 95 facelift. I removed the top screw and the left and right ones around the instrument cluster and then hit a dead end. Would someone mind giving me the rest of the steps to replacing the bulbs?

I tried finding the steps online through a search but could only find the steps for an 80's model XJS. I'm afraid if I try to figure it out myself, I'll end up breaking something and I don't want to do that!

Thanks in advance for the help!

 

Danny,

You really need to buy the proper Jaguar Parts & Service manual on DVD. I wouldn't think about running an XJS without the manual.

If you've removed the three screws, the two plastic side trim pieces can be gently eased out. Then you can remove the two little black blanking plates in the top corners. After that, you can see the two posi screws that hold teh cluster in. You can then pull it forward.

Good luck

Paul

 

In addition to the steps Danny listed, you may also need to remove the two trim pieces that are below of the instrument cluster, on each side of the steering column. Those pieces capture the two side "wrap around" trim pieces at their bottom edges. To remove those trim pieces, there is a single screw that goes up through the trim piece into the side "wrap around" pieces. Then at the very bottom of the two trim pieces, there are two machine screws. Those don't need to be removed completely, they hold two oblong shaped metal washers which clamp the bottom of the trim pieces.


I'm not near my car, so I can't say for sure what is in those trim pieces. I think the RH one contains the external mirror control, and the left one contains the instrument light dimmer knob.


The two little black blanking plates in the top corners (referred to by Danny), and just push into place items. If you can catch the top edge with your fingernail and pull, you can pop them off.

 

Greg,

Tks for adding that. It seems there are some differences on earlier cars. On my mid-94 car, you don't have to remove those screws that come up from the switch panels. The trim pieces came out with just the first screws removed.

Cheers

Paul

 

Paul and Greg,

Thanks for the help. Paul, I took your advice and downloaded the service manual. I wish I had a long time ago! The manual says to first disconnect the ground to the battery before removing the cluster. It is really necessary? The knob to set the time on my dash clock is broken so whenever I disconnect my battery, in order to set my clock I have to note the time on the clock and wait till it's precisely that time of day again before reconnecting my battery so my clock reads the correct time. Such a pain! Haha

I also had to remove the two screws that come up from the switch panels on either side of the steering column before I could remove the side trim panels.

I'll try again this Sunday and hopefully I'll have cool new bright warning lights in my XJS. Oh, the excitement of being able to actually tell if my parking brake is on or not when the top is down...

 

Danny

Good luck with the work. Let us all know how you get on.

Last time, I removed my cluster, I didn't disconnect the battery, but I admit it is good practice. Your call.

As a suggestion, whilst the cluster is out, check, clean and retighten the earth screws for the instrument. They are notorious for giving errant readings on the minor gauges.

Paul

 

I didn't disconnect my battery either and didn't have any problems, I was very careful to plug and unplug the connectors straight out and straight in.

 

Thank you again for the help and advice! I will let you know how it goes.

 

Paul, Danny,

I know this is off topic, but where did you find the service manuals for download?

 

I have removed my cluster about 4 times now, and never disconnect the battery. As long as you do not turn the ignition key on, there is no power going to the cluster.


I have a different problem with disconnecting the battery, but it is easier to fix than yours. My security system no longer has a backup battery (they aren't available, and I haven't gotten around to seeing if I can lash up some kind of replacement). So I have to reprogram my system to my key remotes, and the security code in the audio system needs to be input again.


-Greg

 

Hi Anders,

I Googled my year and "XJS Service Manual" and got several options. I got mine at trade it.com. It was about $11 or $12. Here's the link:

https://www.tradebit.com/filedetail....pair-manual-91

 

Hi Anders,

I don't know about the pirated manual, but there is only one XJS workshop manual for facelift XJSs. It's the Jaguar Parts and Service manual sold through Jaguar Heritage

Paul

 

Pirated manual!? That never occurred to me. I hope not!

 

Danny,

I may be wrong but I am not aware that Jaguar have licensed anyone to sell their copyright Parts and Service information.

Maybe things are different in the US?

Paul