While I had the ski slope off, I decided to do something about the poor illumination of the shifter. While I was attempting to pull the bulb, I discovered one reason that it was so dim was that someone mounted the lamp bracket upside down, so the lamp wasn’t as close as it should have been to the shifter.
But to improve things further, I decided to swap the bulb for a LED unit. There are a lot of options out there for LED units that use a wedge base. Given that any ‘sideways’ light from the bulb is effectively useless in this application, I went with a unit that only fires up and has a narrow beam angle: 32 degrees in this case. Light output is a bit over 10000 mcd from four green 3mm LEDs.
The green filter in the shifter was in rough shape, so I left it out for the time being. If I decide things are too bright, I’ll figure out something to put in its place.
Photos show the original bulb in the holder, the new LED, and how the shifter looks when done (daylight, but not direct sun).
I had a blown bulb in my SI and the replacement was a 24V 3W per the manual. The manual says so explicitly and the Lucas number given agrees.
I removed the old 12V 3W and the new bulb was obviously much too dim. So I ordered a (BA7S in my case) green LED that was much too bright and blueish. Too layers of post-it under the selector cover (on top of the green plastic filter) fixed that. It’s now exactly the same colour and just slightly brighter than the instruments, and just one post-it layer behind the P so it’s a little brighter, perfect.
I used a single larger LED unit and sanded the tip so it was a little matte but that changed nothing.
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
3
It calls for a 24V bulb? Whassup wit dat? They deliberately want it looking weak and pathetic?
Must have been the first bulb that was in there and it’s been a 12V. But the manual insists on 24V and mentions it specifically. Maybe they changed something last minute but I don’t really get it and believe me, 24V was just glowing. Not very visible in the dark. I think the rear window heated warning lamp in the S3s is 24V for some reason?
The LED was too bright but now fits in with the instruments, just how I like it. Anyways I found nothing about the bulb so if anyone else ever has that problem he can find this now.
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24V bulbs in a 12V system doesn’t make sense, David - it basically quarters the light output of a 3W bulb. Which can be as easily done by a 12V bulb of lower wattage
But your solution is just as good anyway - but I’d like to know where and in which manual 24V was prescribed…?
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So am I, David - it is inexplicable, but seems deliberate…
According to calculations; the output of a 3W 24V bulb would be 0,75W at 12V - which, as you observed, seems inadequate. I know that Jaguar was concerned with the heat generated by the Opticel set-up - which may be the reason for the choice? But on the other hand; if the light output was as bad as you indicate - it seems a bridge too far? Or have the Opticel lay-out deteriorated over time…?
It’s not opticell, it’s just a brass cap with a little hole that shines onto a green filter and then through the letters on the selector quadrant…
Even then as you say 0.75W of orange light go nowhere. And the Lucas 283 checks out. Strange.
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
9
It’s worse than that, actually. The normal formulas for watts and amps don’t apply to an incandescent light bulb because the filament gets so hot as to significantly change the ohmage from room temp. The point is valid, though: only some tiny percentage of the rated wattage will apply to the bulb, and that is going to appear weak and yellowish rather than crisp and bright. It makes no sense at all.
What would make more sense to me is that some nimnul at Jaguar wrote down the wrong number and it got faithfully carried forward from one document to the next.
If you look at the table of bulb types on my picture they also put the 2.2W instrument lamps as 22 watts each (!) and forgot a „)“ so it might have been rushed into print or forgotten about until it was too late.
Maybe some nimnul took a 281 bulb for a 283 on the hand written data for the printer, then he looked into the Lucas catalogue and saw that it was 24 volt, then added the note to use a 24V based on this chart, and made the plates.
Or they started out with a 24V and realized how stupid that was after the first batch of manuals was done. But I am still curious if there once was a good reason why it could have been 24V.
Hey, the filament lit up brighter than the burnt out one. Faintly orange
For the next guy this looks perfect with two strips of yellow post-it as a filter. Better match than on camera.
When I was in that space during the lump project, I noted that bulb was busted. I found one that fit. Watts, I’ve not the slightest. Works, although, I rarely look, just feel the detent. And it’s location.
Opticell? i think mine is bonkers. had no idea as to what that was when first in there.
After, more visits for window switches, i got distrated as I had intnded to check that out.
Opticell, I put in the brightest LED I had, that made a big difference over the already modified halogen bulb, and that difference was from not noticeable to barely noticeable.
I made sure the cable ends were clear and not burned.
Thankfully, the Opticell arrived with the S2, so I no longer have that problem. I recommend a very bright LED if you need to see the things it lights up (or put in tiny individual LEDs if you have the time). But it’s easy to live without. Really best to leave it unless in the area…
Back to the S1 the shifter detent pawl of the selector lever is very worn (no need to push it to the right either) so I still need a little confirmation for my own confidence, and of course for other drivers who are not as familiar with the thing. Also helps me know if I‘m in D1 or D2 (the transmission is like the „green dot“ Ford transmissions you should be familiar with). I switch between those two a lot.
My LED is now failing and I’m going back to the original incandescent bulb. Usually prefer the original way and still make these mistakes again and again. The incandescent will last decades longer than the transmission (especially with its manual replacement waiting already).
