Author Topic: Clock bulb - BA7s vs BA9s  (Read 2881 times)

Rahul

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Clock bulb - BA7s vs BA9s
« on: June 21, 2021, 15:47:31 »
I was wondering how people are able to fit a BA7s bulb into the clock.

I bought a BA7s LED replacement following the advice in the technical manual, and in this forum post: https://www.sl113.org/forums/index.php?topic=23986

I just cannot see how you fit a BA7s bulb into here, I tried and it went straight down the ~10mm hole and rattled around inside the clock housing! The existing BA9s bulb fits perfectly, and not too tightly... the BA7s is far too narrow.

Is it possible that earlier models accepted a BA7s bulb whilst later model cars only take a BA9s?
1971 280SL auto #571 over parchment

lreppond

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Re: Clock bulb - BA7s vs BA9s
« Reply #1 on: June 22, 2021, 05:17:30 »
I have no idea how to do this!  My intent is simply to give a shout out for the wonderful way you're restoring your car.  Between the new interior and final finishing touches like replacing a lamp inside the clock I bet your car is really coming into its own.  Do us all a favor and share pictures.   

Bravo!
~Len

1971 280 SL
576G red/251 Beige
4 speed manual
Family owned since new (father —> son)

Rahul

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Re: Clock bulb - BA7s vs BA9s
« Reply #2 on: June 22, 2021, 07:42:21 »
Lol, thank you - I took the view that if the car was going to be taken apart and be out of action, I would like to do as much as possible to (hopefully) prevent me from needing to pull it apart again for a while!

I spend far more time on this site than is healthy, ​and I am truly amazed at the rabbit warren of information stored here. The forums and the people that take the time to reply have taught me so much about the workings and the history of the car, and made ownership a very enjoyable experience.

I hope to post photos next week when the final upholstery bits are completed. Appreciate the support!
1971 280SL auto #571 over parchment

66andBlue

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Re: Clock bulb - BA7s vs BA9s
« Reply #3 on: June 26, 2021, 06:25:06 »
I was wondering how people are able to fit a BA7s bulb into the clock.
I bought a BA7s LED replacement following the advice in the technical manual, and in this forum post: https://www.sl113.org/forums/index.php?topic=23986
I just cannot see how you fit a BA7s bulb into here, I tried and it went straight down the ~10mm hole and rattled around inside the clock housing! The existing BA9s bulb fits perfectly, and not too tightly... the BA7s is far too narrow.
Is it possible that earlier models accepted a BA7s bulb whilst later model cars only take a BA9s?
Thanks for questioning the information in the technical manual and highlighting your problem. You were right, a BA7s does not fit into the clock! The technical manual information was wrong and is now corrected. I have also corrected my reply in the link that you provided.

The reason for this error probably arose because of a mistake in the Mercedes spare parts lists that show the same part number (07601 012800) for the bulb in the clock and also for the 2 bulbs in the heating/ventilation controls.
However, the latter are BA7s bulbs and the correct Mercedes part number is 07601 012110. It is unfortunate that Mercedes never corrected this printing error and I do not know whether it carried over into the EPC.
I hope you went ahead and put the BA9s bulb in and all is well.

Alfred
1964 230SL manual 4-speed 568H signal red
1966 230SL automatic 334G light blue (sold)
1968 280SL automatic (now 904G midnight blue)

Pawel66

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Re: Clock bulb - BA7s vs BA9s
« Reply #4 on: June 26, 2021, 07:12:13 »
In the EPC bulbs are not drawn on the picture, they are just in the parts list.

For Instruments and switches, you just have:

   
N 072601 012800 BULB 12V/2W 7pcs needed - below the gauges.

Then further down:

under speedometer, same bulb, 2pcs and socket number for it A 000 544 25 93.

under tachometer, same bulb, 2pcs and socket number for it A 000 544 25 93.

under clock N 072601 012800, 1 pc.

In the Heating and Ventilation we have as well

N 072601 012800, 2cs - which is the same PN as in the instruments. Looks like the mistake was left uncorrected in the EPC.

Pawel

280SL 1970 automatic 180G Silver
W128 220SE
W121 190SL
G-class