280sl alternator part number

[VincentR]

Hello All,
Do you know the original part number (MB & Bosch OEM) for the Pagoda 280SL Alternator?
Thanks in advance.
Best regards.
Vincent R
280 sl 1970 France

[mbzse]

.../... original part number (MB & Bosch OEM) for the Pagoda 280SL Alternator

Alternator: Bosch 0 120 400 504  K1 14V 35A  20  (also: Bosch 0 120 400 606)
/Hans in Sweden

[Naj ✝︎]

Hello, Vincent,

Do you know if your alternator is 35 amp or 55amp?

Earlier cars had the 35 amp alternator Bosch # 0 120 400 606. These are NLA.

The 55a alternator is available as a remanufactured unit Bosch # 0 986 031 020 (with integral regulator) and uses the 3 flat blade euro plug.
The last time I checked, the price from Bosch was around €500.00. Sometimes you can get Bosch rebuilt units from Valeo # 436121

naj

[VincentR]

Hello Hans and Naj,

Thank you for your answers.

@ Naj : my 1970' 280SL is fitted with one regulator (new version in electronic I fitted from from Bosch ) on the front right inner wing : is it compatible with the new (integrated regulator) alternator?

Best regards.
Vincent.

[Naj ✝︎]

Hello, Vincent,

If you change to the alternator with the integral regulator, then the separate one becomes redundant.

The alternators are the same, the only difference being the brush plate. One has three spade terminals and uses the external regulator or the other one has an electronic regulator built into the brush plate and you only need to connect the blue wire (operates the warning light) from the loom to the separate D+ terminal on the alternator with the integral regulator.

naj

[VincentR]

Hello Naj,
Thanks for your information.
Is the current brush plate (w/o integrated regulator) compatible with the new alternator (to enable to still be in external regulator confirguration even with the new alternator) ?
Best regards.
vincent

[johnk]

I recently purchased a rebuilt 55 amp Bosch from FCP (FCPEURO.com) for $70 which fit perfectly. It was a Bosch AL72X and works great.

[Naj ✝︎]

Hello Naj,
Thanks for your information.
Is the current brush plate (w/o integrated regulator) compatible with the new alternator (to enable to still be in external regulator confirguration even with the new alternator) ?
Best regards.
vincent

Hi, Vincent,

If your alternator looks like the one in the pictures, then yes

[VincentR]

Hello All,
Thank you for your information.
I will keep you informed.
Best regardS
VincentR

[Erics]

Resurecting an older thread...

Will this fit a 1968 280sl?

http://www.mister-auto.co.uk/en/alternator/valeo-436121_g4_a021436121.html

[Naj ✝︎]

Resurecting an older thread...

Will this fit a 1968 280sl?

http://www.mister-auto.co.uk/en/alternator/valeo-436121_g4_a021436121.html

This alternator is for later model cars, W114, W123 etc.

Your car is probably fitted with a 35a alternator which Bosch no longer supply (but can be rebuilt). You can change to a 55a alternator but you will need to modify some of the wiring. The 55a alternator is MB 003 154 6202 or equivalent.

naj

[Erics]

This alternator is for later model cars, W114, W123 etc.

Your car is probably fitted with a 35a alternator which Bosch no longer supply (but can be rebuilt). You can change to a 55a alternator but you will need to modify some of the wiring. The 55a alternator is MB 003 154 6202 or equivalent.

naj

Hi Naj and thank you very much for the kind comment.

Here are a few pictures of the potentially faulty alternator. If you could please help me to identify it.. Like this i could try and find the exact replacement part..

[Erics]

Whilst i wait for someone to tell me what the above alternator is (35a or 55a??).

The AA guy came yesterday and helped me jump start the car with spare cables. When flat the (brand new) bosch battery gave 11v, so been clearly drained.

At idle, it gave 12.2v. I would have thought if alternator dead it would give 11v at idle too.

The fact that it gives some voltage means that it may be something else? Regulator? Any idea?

[Naj ✝︎]

Hi, Erics,

Yours looks like a 35a alternator.

To change to a 55a alternator with an internal regulator, you will need a 3 blade Euro plug. The 2 B+ wires go to the 2 wide blades. Use the D+ wire from the old 3 pin plug. The old regulator becomes redundant.

naj

P.S: Here is a link to an after-market 55a alternator.

Note it does not have an internal regulator. To use it, you would have to change your 3 round pin plug to a 3 flat blade plug and use your old regulator or change the brush plate to one with an internal regulator. You would still need the 3 pin Euro Plug for the B+ wires.

http://www.woodauto.com/Unit.aspx?Man=BOSCH&Ref=0120400723

naj

[Erics]

Thanks Naj, going to specialist on Wednesday...

[Erics]

Quick update on this. I spoke to Simon at the SL shop re what could have happened to my brand new alternator.

His opinion is that the wires going to the alternator melted due to going the 'shortest way' from the right hand side wing to the alternator.

In his opinion, this got the wires too close to the engine headers and melted the wires.

The 'right' way to do it apparently is to route the wiring loom the 'long' way which is supposedly from the top of the alterntor and keep any wiring as far as possible from heating source in the engine bay.

Apparently, it is a common mistake that restorers make. I was not aware of it and my alernator is presumably kapput as a result.

Better be informed then...