I just replaced all the Warning Light Cluster bulbs with LEDs. That was a significant project that I'll talk about in another thread.


Of all the original bulbs in the cluster, only the "Sport" mode bulb was burnt out. Now I know why.


The "Sport" mode light stays on dimly all the time. It comes on bright when the "Sport" mode switch below the shift lever is selected. And the Sport mode is definitely working when selected. I can feel the difference in the shifting.


As best I can tell from the schematics, the "Sport" mode warning lamp gets it's power from the Transmission Control Unit. The "Sport" mode switch does not send power to the light. It seems to complete some circuit in the Transmission Control Module. And that module appears to send power to the LED at the Sport mode switch, and the cluster light.


I suppose that the power "leaking" to the cluster Sport mode lamp may be coming from within that assembly. It is an astoundingly poorly designed unit, and would not be surprised that a lot of people have problems with it.


Or, perhaps the leaking power is coming from the Transmission Control Unit.


I'm inclined to think it is in the lamp cluster unit. The LED near the Sport mode switch is not being effected. If the power was leaking from the Transmission Module, I would think both LED's would exhibit the same problem.


Anyone have any similar problems?

 

On an xjs?

 

That's odd, I had to change my Sport mode bulb on my 4.0 just the other day, the only bulb I have ever had to replace, but mine doesn't stay on (even dimly). The only time mine is on is when Sport mode is actually selected and then it's the same brightness as all the other bulbs. I just decided the original owner must have left it in sport mode allot.

I wish I knew an easy way to brighten up ALL of my dash indicator bulbs so I could see them during the daylight.

 

Yes, it's a '93 XJS convertible 4.0L automatic

 

Changing the warning lights to LEDs did the trick. But it wasn't exactly easy. The original bulb leads are soldered to contacts in the plastic twist-to-lock receptacle. It's possible to remove the bulbs and contacts, then clip the old bulb leads. Reassemble contacts into the twist-to-lock receptacle, insert the LED, and solder the leads to the contacts. It was a long process but I can now see the warning lights in the bright daylight with the top down.

 

Do you remember the part # of the LED's you used?

 

They didn't have a number on them. I purchased a kit from V12s.com, which cost about $100 for all the LEDs in the warning cluster. It was, frankly, a rip off. With a little research, one could probably get the same LED's for about $2.00 each.


On top of the exorbitant cost for the kit, the instructions were very general in nature, and I was under the impression that the LEDs just inserted into a socket that the bulb was pulled out of. NO WAY.


The bulbs are soldered to the contacts in a plastic twist lock carrier. I figured out how to disassemble them, and solder in the replacement LED's. But it was very tedious and time consuming. I have a good background in electronic assembly and have an appropriate sized soldering iron for the job and some tools to hold the unit while I solder.


I have started looking online, and it looks like there may be some LED's already mounded in little twist lock carriers. But I can't tell for sure. The catalogs give some dimensions. But my Instrument Cluster is all reassembled now, so I can't make any comparisons.


But, they sent me two LED's of the wrong color. I sent them an email asking for replacements (as well as letting them know that I was displeased about being led to believe they were a plug-and-play replacement). I haven't received a response. But If I get the correct color LED's from them, I'll have to take the unit apart again to finish the job. As it turns out though, the missing replacements are for a couple of lights that are almost never used. So the dim bulbs that are there now will be OK until I can finish.

 

Is the problem that Jaguar just used under-powered bulbs? Because I have owned another vehicle (a Jeep Grand Cherokee) that had those same twist bases with bulbs soldiered to them just like in the Jag, looks like the same thing, only in the Jeep they are plenty bright. Maybe they use a different bulb, wonder if they would fit in, from what I remember they appeared to be the same size.

 

Wonder if these would fit...

PC74 LED Bulb - Instrument Panel LED | LED Replacement Bulbs for Cars | 12v | Super Bright LEDs | Super Bright LEDs

 

Those do look very similar. Without an original bulb assembly in hand to measure, it's hard to say for sure.


There is a similar bulb assembly that is bigger and I guess illuminates the instruments in the cluster. This might be a replacement for those if they don't fit the warning light cluster.

 

I'm not sure, It might be a combination of a low wattage bulb, colored lenses that are not very translucent, and reduced actual wattage due to what appears to be common ground faults.


Also, I had to laugh when I read somewhere (I think it was in some original sales brochures), that Jaguar proudly referred to the instrument cluster as "Invisible until lighted", or something of that nature.

I think their efforts to make the cluster "Invisible" worked a little to well!

 

Got a transmission/shifting question. My symptoms:

- for a few weeks before my x-country drive, I'd been noticing the transmission felt a little lurch-y at low speeds for a few minutes after cold start-up, and fought me a little bit on kickdown. Both of these seemed to get better after the car was warmed up.
- At the end my first long day of the drive, I got to the base of a freeweay offramp, but did not need to come to a stop (I think that matters). When I started to accelerate back into traffic, the car started lurching, in that way that cars would lurch when you were learning how to drive a stick and you'd just drop the car into gear. At this point I was going maybe 10, 15MPH. Wondered if the car was still in 6th? Put it into neutral, revved the engine a bit, let it go back to idle, put it back into D. That seemed to help but still felt wonky. Never had this happen before.
- This happened a few times again, always when driving at slow speeds after hours of high-speed highway driving.
- other disturbing thing that started to happen during the end of the trip: REALLY harsh downshifts at highway speeds. Like I'm going 60, move to pass, hit the gas hard and the downshift kind of slams into the lower gear. Like I feel a harsh, almost violent thunk/knock on the kickdown.
- finally, now that I'm back east and doing shorter drives: on those occasions when I try Sport mode, the car will go to almost 6,000 rpms in any gear before a shift. Again, never had this happen before.

It might be optimistic to think a simple fluid change would help all this, but would it be worth it to try? Any other thoughts?
Thanks as always...

 

pk4144,

This seems to be in the wrong model section and added to a completely different thread?

Paul

 

Maybe.

I bought a ton of neo5 bulbs from them and the base is ju-u-u-ust too big for the opening.