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MG Midget and Sprite Technical - Light bulb codes

Can someone give me a brief tutorial on how to read the codes used for light bulbs please.

I need some dashboard gauge lights. (Not LED!) I have twice got the wrong ones. The first pack of 10 appeared correct but when I tried to fit them I find that the glass globe is too big to go into the hole in the gauges.
The second batch of 10 look right in the photo and were referred to as small, but there was nothing to scale the picture against and they turn out to be about 50% oversize for the bulb holder.
GuyW

You want GLB987 I guess that's both a
BL and Unipart number. It's in the handbook....
ETA v- that's the later handbook, hope early marks are the same?
;-)

Think the Lucas equivalent is LLB987.
https://www.ebay.co.uk/itm/10-x-LUCAS-LLB987-BULBS-used-in-SMITHS-GAUGES-12v-2-2w-MES-E10-SCREW-BASE/153898793980?hash=item23d5153bfc:g:xPcAAOSwKU1elwNT
What have you had that doesn't fit?
David Smith

Guy If you mean the screw in 2.2W bulbs the Lucas number is 987. This is a universal number so even euro car parts stock it under that number! The oil/water and fuel gauge are externally lit so bulb globe size is less critical but its the same bulb all the same.

Bob Beaumont

Thanks.
I thought perhaps There was a formula that could be interpreted.

The oversize globe ones are screw threaded, as I expected, 12v 6w (more than I expected) coded A10
The other ones are bayonette, but too fat to go in the holder. Code on the box is BA15s I am guessing That the 15 denotes the diameter as in 15mm.

I can look for a supplier using the codes you have given, the 987 number, But I thought maybe there was a coding system to learn!
GuyW

Best deal I can see on ebay tonight is £5 for 10 bulbs + £1 postage. Moss only charge 66p a bulb but there's postage of course. I *think* the main beam and ignition lights are the same on the older speedo and tach but different on the later ones. I haven't ordered bulbs yet.
Bill Bretherton

There are books with the information of the bulbs you need (called Driver's Handbook). ;)

As above posters have put, but from Frogeye DH -

Panel light bulbs - 12v - 2.2w - Lucas (LLB)987 and BMC Part No. 2H4732.

For car bulb 'caps' - I KNOW you don't want LEDs but this is from Classic Dynamo & Regulator Conversions Ltd led bulb information which applies to incandescent too obviously, I've added in brackets for more detail.

. E10 or MES is a 10mm cap screw in bulb - (E stands for Edison as in Edison Screw (fitting) and MES is Miniature Edison Screw)
. BA7s is a 7mm cap with a single contact - (BA is for Bayonet, s is for single contact on the bottom of the cap)
. BA9s is a 9mm cap with a single contact
. T10 is a 10mm cap push in fitting
. BA15s is a 15mm cap with parallel pins - (single contact)
. BA15d is a 15mm cap with parallel pins - (double contact)
. BAY15d is a 15mm cap with staggered (offset) pins - (one pin sits higher than the other)

GLB987 is a E10MES - so Miniature Edison Screw, 10mm diameter (I know this because I looked up GLB987 on the Classic Car LEDS Ltd website!).

A few websites will give the dimensions of the bulbs, the glass as well as caps.

For household - https://blog.lightbulbs-direct.com/your-guide-to-light-fittings-caps-and-bases/

If you want more info just ask (or look in a book). :)
Nigel Atkins

Thanks Nigel. I did just ask! And you have now given the detail I needed to translate the codes. I can now read 'bulb'

I will have another go at ordering tomorrow and see what turns up this time. It's quite exciting really!
GuyW

Bill your correct!

The frogeye uses the same 987 screw in bulb for all the dash light fittings.
Bob Beaumont

Guy,
you're only fluent in certain dialects of bulb, there are others.

Just using the Driver's Handbook would have got you what you wanted first time.

I couldn't find the sites with the bulb dimensions this time but have in the past, general suppliers sites I think.

I must admit the LES - Lilliput Edison Screw (E5) was new to me so I've learnt too - but will forget with the next blink of my eye


... what was I doing?

ETA: Guy, be careful about buying cheap bulbs some are crap and may break at the cap getting them in and taking them out when they blow. Incandescent bulbs for brake lights and indicators you want to buy 'heavy-duty' or 'long-life' or some such description as standard often just means crap/short life.
Nigel Atkins

Steady Guy, contain yourself, don’t get silly with too much excitement now !
Chris Madge

Chris, after 2 months in lock down you have to take your thrills when you can get them!
GuyW

This thread was discussed between 17/05/2020 and 18/05/2020

MG Midget and Sprite Technical index

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