Instrument Illumination

[stugilmour]

Can someone with their dash out confirm the dimensions of the stock bulbs and the amount of clearance in the instruments, large and small? I think they are similar to the AES link above with 10 mm screw base, 11 mm round glass globe diameter, and 23 mm (0.906 inches) overall length. Note the 6 w bulbs are 14 mm globe diameter and might be difficult to fit?

Here are a couple of LED possibilities I found thru an MG forum that discusses this issue. Unfortunately they are a bit short on a 'I used this exact part number and it worked great' concluding post, although the last link comes close. There are a few positive remarks about the LBC Halogens as well. The second link below was pretty interesting comprehensive listing for all the side marker, reverse lights, etc.

http://www.mgexperience.net/phorum/read ... sg-2038438

http://www.mgexperience.net/phorum/read ... sg-1802512

http://www.mgexperience.net/phorum/read ... sg-1812228



Some selected LED's from the last link

This first one comes in various colours including warm white. It is billed as Bi-Polar, which might work with positive ground. I believe the T3-1/4 designation refers to the tubular glass diameter in eighths of an inch, which would be 13/32" or a nominal 10 mm. I think this diameter should fit in the small instruments and the warning lamp barrels. I believe the stock bulbs are G3.5, or a nominal 11 mm glass diameter. Although the bulb length is not stated, the pic looks promising with the flat face on the tubular glass.

http://eliteled.com/products/lightbulbs ... dbulb.html

T3-1/4 (10mm) Miniature Screw (E10) Base LED Bulb

Pic of Elite LED dash bulbs.jpg (5.66 KiB) Viewed 6917 times

T3-1/4 (10mm) Miniature Screw (E10) Base LED Bulb:
? Patented ?pseudo filament? provides 360 degrees viewing angle
? Bi-Polar design, simple plug in, no need to worry about ?+? or ?-? direction
? 3-in-1 smd LED packaging - 3 LED dice inside each bulb
? Operates at 6 V, 12/14 V, or 24 V AC/DC
? Long Life span 100,000 hrs, No need to change light bulb any more
? Shock / Vibration resistant
? Available in White, Warm White, Blue, Green, Amber, and Red colors

Sale Price: $6.95 each in 12v

This second one comes in White only. Outside diameter and length might not fit in the small instruments or the warning light barrels.

http://www.ledlight.com/e10-screw-base- ... -bulb.aspx

E10 Screw Base 5 5050 SMT LED Light Bulb

Pic of LEDLight dash bulbs.jpg (11.34 KiB) Viewed 6917 times

E10 Screw Base 5 5050 SMT LED Light Bulb
Product Code: 57567
Price: $8.99

E10 Screw Base 5 5050 SMT LED Light Bulb.
5 5050 3 chip LEDs.
Very nice product for E10 screw base applications.
12 Volt direct current.
Available in white only.
Approximate size is 1.15in x .45in. (29.2 mm x 11.4 mm)

Another pretty cool link. This supplier has a pretty complete listing of incandescent bulbs with dimensions. Plug in 12 volts and base E10 to get a complete listing. Looks like a lot of the higher wattage ones might be NLA.

http://www.donsbulbs.com/cgi-bin/r/t.pl

[stugilmour]

Excellent thread; glad the discussion has been renewed.

I'm wondering if part of the problem with the factory setup is the voltage regulation and lack of full voltage to the lights due to grounding or worn-out/improperly adjusted voltage regulator??

Just a thought . . .

Randy

Randy, were you thinking of the voltage stabilizer or perhaps the lame regulator on the stock generator?

Anyway, the instrument bulbs use Red / White wires from the panel switch, which is supplied from the side light switch (Red) at a full 12 v. Only the fuel gauge movement, the temp gauge movement (in the plus 2 electric type) and oil temp (if fitted) use the 10 v supply from the stabilizer.

http://www.lotuselan.net/uploads/smiths ... wiring.jpg

Even with my completely new wiring, good grounds, and alternator the dash lights are really too dim to be practical, hence the desire to find something brighter. I checked my voltage at the bulbs when I put the dash in and it was good, so seems to be a 'they are all like that' deal.

Cheers!

[ricarbo]

I typed up a long (for me) reply, but it doesn't seem to have appeared. perhaps it will later. In short, the manual lists the correct panel lamp as a 987 (2.4 watt. E10 or MES base, 10mm thread, 11mm globe and 23mm length). Richard (Higs) link to better car lighting shows a led substitute, that looks great, made for the job.
I think higher wattage incandescents would be potentially unsafe. the circuit needs a fuse, if you ask me.
Richard

[Sea Ranch]

Again I say, awesome thread and info.

Thanks for the clarification, Stu. Yes, I was thinking of the voltage stabilizer and I thought it fed the dash lights (didn't look at my schematic to see ). I'm sure you're right; my dash lights are very dim, too.

[Higs]

Another link for uk owners:

http://www.rapidonline.com/Electronic-Components/12v-Warm-White-LED-Bulb-1960mcd-100-41-0842#techSpecs

I think this is close to ideal (happy to be corrected) - 12v, warm white, wide viewing angle, negative earth.

I did notice from the three MG links above two interesting things:

1. (Thread 2) They soon descend into squabbles about what car/year certain features were introduced (we are not alone!)
2. There was interest in colours other than white for their instruments (any takers here to be first to suggest another colour for an Elan....?)

Richard

[gherlt]

regarding the bulb from rapidonline I would like to highlight the indicated power rating:
240mW, as a guidance I use a factor of 8 to 10 to calculate the equivalent "old" power rating,
which in this case would give 2.4 W. Not much more than the old 2W bulb.

I did try once a 200mW LED (not sure of the angle, though) and it was as bad than the old one.

[gherlt]

We need something like this:
http://www.ledlight.com/e10-screw-base- ... light.aspx
http://www.ledlight.com/e10-screw-base- ... -bulb.aspx
http://www.ledlight-ledbulb.com/html/Au ... s/237.html

They have 0.4W rating, this could be a 50% increase ...

[ricarbo]

Frank, I think you need to be very wary of fitting larger incandescent lamps, because of the heat they produce. Look at this

http.doc

(19.5 KiB) Downloaded 501 times

. ok, it's about MG's, but our wiring is similar, that circuit has no fuse and the car is fibreglass, so the fire hazard is worse. I don't think extra heat is very kind to the electronics in the tacho, or the 50 year old plastic, either. An inline fuse looks well worth it's small cost.
Richard

[oldelanman]

Can someone with their dash out confirm the dimensions of the stock bulbs and the amount of clearance in the instruments

On the small instruments (at least the oil pressure gauge which is the only one I can easily get to) only around 4mm of the bulb intrudes into the instrument case itself, the majority - including the filament - remains inside the mounting tube. This could be why the illumination is ineffective. In the oil pressure gauge there is not sufficient clearance for the bulb to intrude further because the bourdon tube runs very close - can't say if this applies to the fuel gauge as well. Maybe a 360 deg LED is not necessary in this application as the sidefacing elements would be inside the tube anyway.

[Frank Howard]

Frank, I think you need to be very wary of fitting larger incandescent lamps, because of the heat they produce. Look at this

http.doc

. ok, it's about MG's, but our wiring is similar, that circuit has no fuse and the car is fibreglass, so the fire hazard is worse. I don't think extra heat is very kind to the electronics in the tacho, or the 50 year old plastic, either. An inline fuse looks well worth it's small cost.
Richard

Richard,

I watched the video. There is nothing in the video that indicates that the wiring meltdown was caused by fitting a larger incandescent lamp. As a matter of fact, Twist said that the meltdown was caused by a dead short in one of the bulb holders. Twist made no mention of larger bulbs being used in the MGA. Did a larger bulb cause the holder to short? How could it if larger bulbs were not being used? Obviously, something else caused the bulb holder to short out.

You say that you don't think extra heat is very kind to the electronics in the tach. What do you base this on? Have you installed larger bulbs in you car and witnessed any failures? I suspect that this is simply your opinion.

I have actually installed 4w and 6w bulbs in my car and I have found that the larger bulbs have absolutely no effect on any of the instruments except for the fact that I can see them now. I've had the larger bulbs in for 6 years and I have taken my car on extensive trips, sometimes at night. No problems. My recommendations are based on actual real life use. They are not based on my opinion.

I even added a new Smiths ammeter to my car. Rather than being constructed of metal, the can is now made of plastic. The ammeter came from the factory with a 4w bulb and the bulb holder is plastic as well! Do you honestly believe that Smiths is currently putting out instruments that are fire hazards?

As far as fuses are concerned, I ditched the 2-fuse box years ago and replaced it with a 16-fuse box. My dashboard light, parking light, side marker light, tail light circuit is protected by a 10 amp fuse. It has never blown.

There may be legitimate reasons for installing LEDs but reduced heat is not one of them.

[stugilmour]

Thx Roger. Excellent info on bulb clearance in the small gauges.

Here is another incandescent possibility from LBC. The web site uses frames, so you have to scroll down about a quarter of the page to see the actual listing link. It is listed as a new product. From the pic the clearance looks good for both glass tube diameter and length. From Frank's reports these could fit the bill for the large gauges. I really like only $7.00 each.

http://www.lbcarco.com/specialf.html

=======================================

8w Tungsten Dash Bulb

Now get more light from your dash instruments for a lower cost than our Halogen Dash Bulbs. These 8w Tungsten bulbs will help you better see your instruments at night. Keep in mind they better than the standard tungsten 2.2w bulbs, but still no where near as good as our 5w or 10w halogens since the tungsten light is not as bright and white.
Priced at only $7.00 each

8w Tungsten Dash Bulb - E-10 Screw in Base

======================================

For the colour choice, I actually tried some green incandescent bulbs when I had the dash out. Didn't really work that well as they were pretty dim and the instrument lettering was harder to read. Not sure where I got them or their wattage. Thinking Warm White would look most 'stock'; oh forgot, we are trying to get away from stock!

Another upgrade route similar to Frank's original post and change to bayonet may be to change out the bulb sockets to capless bulbs, which appear to be more available in higher wattages. British Wiring in PA seems to offer some, but not sure about any fitment issues. I recall considering these during my dash re-build, but cannot recall why I didn't follow through. One minor issue I can see is having to add ground wires to the plastic bulb holders; could probably be run to ring connectors on the gauge mounts to connect with the existing grounds. It's easier to post a link to their new site.

http://www.britishwiring.com/Bulbs-Bulb ... 100&page=1

The same products appear to be offered at Autosparks in the UK

http://www.autosparks.co.uk/index.php?cPath=90&page=2

Great thread. Really getting lots of options.

Cheers!

[ricarbo]

Frank, well, I'm pleased to hear you have fitted fuses.
I agree that the clip from University Motors doesn''t assert that oversize lamps were the cause of the failure, just that the lamphoder went short circuit, cause not given, it also says it is not common. The result in the unfused circuit was catastrophic, which is why I advocate fusing where there was none before.

Yes, my view is that heat damages plastics and electronics.

The plastics go brittle and break, I expect most of us have had to replace heat damaged lamp holders at home, I know I have. It's why I am compelled by law to have special heat resistant cables for my kettle, my hot water cylinder and some of my lights, etc, even though they are fused. It's why I had to replace my cooker door seal last month. Components like the electrolytic capacitors found in the tacho rely on a paste to isolate the internal plates and this gets dried out with heat and time, the soldered joints get stressed, the old germanium transistors don't like heat, the carbon resistors split open. Newer components are tougher than these old style devices. Heat and time is the enemy for all these things. It's why my television, toaster and computer have ventilation. These instruments are also old, if original, so have done well to last as long as they have.

That's why I think you should try to give them the easiest time you can, why I say you should be wary and, for me, that would include not putting in 6 watt lamps when the manufacturer used 2.4 watts. If the successors to Smiths fit 4 watt lamps in their current range, that's fine with me, we should be able to trust them, but I would definitely prefer a cold LED to a very hot incandescent, for a long, reliable, problem free life.
Richard

[Frank Howard]

you should be wary and, for me, that would include not putting in 6 watt lamps when the manufacturer used 2.4 watts. If the successors to Smiths fit 4 watt lamps in their current range, that's fine with me, we should be able to trust them...

Richard,

Just to set the record straight, the manufacturer used 2.2-watt lamps, not 2.4.

The successors to Smiths currently fit 4-watt bayonette style lamps in their small plastic 2" diameter gauges like my ammeter. I don't know what they fit in the large gauges because I have not ordered a new speedo or tach from them however taking into consideration the fact that the volume of the large gauges is 4 times that of the small ones, if fitting 4 watt bulbs to the small gauges is "fine with you" and you are able to "trust them" on this, fitting a 6 watt bulb into a gauge that has a volume that is 4 times larger should be fine with you as well, especially if the larger gauge is of metal construction.

I understand that heat is the enemy of electronics. I just don't believe that the extra heat generated by a 4 or 6 watt bulb is significant enough to cause any damage at all. If that were so, my gauges would be damaged by now. I don't believe that Smiths tested several bulbs and learned that 2.2 watt bulbs generated the maximun amount of heat that the gauges could handle.

[holywood3645]

I looked through RD site and came across the item below. The 5/8 bulb holder may be a solution to the dim tach and speedo issue. There appears to be a good 12V selection and wattage options for this style bulb holder. The question is will it (5/8 holder) fit the speedo and tach.

James

[holywood3645]

I just received these 8 Watt Tungsten Instrument bulbs from the Little British car company Farmington Hills MI 48334. They appear to be great and a LOT better than the orginals. See pic
The fuel Gauge is brighter than the Oil/Water temp gauge. I'm not sure if the orginal items, the white ring appears to transmit to much light. The Speedo and Tach are a closed items for me with this solution... I like it!

Little British car company Farmington Hills MI 48334
Item Code 171-0008WDM /$7 each

Any ideas of the gas gauge?

James