1969 911E - Alternator Light

I have also a 69´s 911E.

Check this :
https://www.early911sregistry.org/fo...-compatibility

You have to check if your alternator is a SEV Motorola/Marchal or a Bosch because the regulator is different.

Attachment 596936

Here is what yours should look like. The only good thing I see is what appear to be headlight relays, although poorly wired in.

Thanks all - hopefully we are getting somewhere.

I pulled the fan, housing, and alternator tonight and the alternator has seen better days, though that doesn't mean much. Any idea which one this is? I'd rather not separate the housing and fan yet, but may be headed that direction.

My wiring:

Big red wire with white stripe connected to B+
Small red wire connected to +61
Black wire with tape labeled "DF" connected to DF
Brown wire connected to D-
Ground strap connected to case

There also did not appear to be an inner air guide - were these early cars equipped with them?

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You can take it to be tested, and that’s a good idea.

And there’s a pretty good chance, you just clean it up and it will work.
Do your best to check and fix bad wires, and wires that don’t look like they’ll last much longer.

Pulled the alternator out of the housing and took the fan off. No markings other than this tag from a rebuilder. Did not see anything that would indicate Bosch or SEV/Motorola, etc.

Going to take it to a local shop for testing.

Is this alternator worth rebuilding if it ends up being bad?

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Those look like fine threads on the shaft, that would make it a Marchal. And the Bosch alternator usually had a riveted on I.D. tag.

This is what you should have on your 69's 911E :

Attachment 596952

The big red/white on B+ goes to the batteries.
The red on D+/61 goes to the regulator.
The brown on D- goes to the regulator.
The black goes also to the regulator.
The grey is a ground going to the engine top case.

The regulator you can find for a SEV Marchal or Motorola looks like that :

Attachment 596953

As you can see the little red wire coming from the alternator is jumped with a blue wire that goes to the dashboard red light.

The good wiring is here :

Attachment 596954

My alternator was in a very bad shape but still working (I replaced it of course) !

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Quote:

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Originally Posted by edmayo

Those look like fine threads on the shaft, that would make it a Marchal. And the Bosch alternator usually had a riveted on I.D. tag.

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If it is indeed a Motorola type alternator, and someone has spliced in the three prong connector to accept a Bosch style VR, then perhaps that is my problem.

Anyone know if I can simply add the Bosch style alternator since the VR harness has already been adapted? Or more complicated? Should I still have this alternator tested/fixed?

Here is a better photo of the VR harness that has been hacked to accept a Bosch style VR.

Attachment 596963

After a bit more research, I suspect this is my problem:

A prior owner was having charging issues and either couldn't find a SEV/Motorala type VR or thought the Bosch-style VR was superior and modified the harness to accept it. However, they did not to match the VR with the alternator. Thus, we now have a Bosch VR combined with a Motorola alternator, and I have read that the Bosch VR has a lower set point than the Motorola alternator requires, so the battery is slowly discharging over time. This would explain why there was no light when the car was fresh off a battery tender, but once the battery slowly drained enough, the light came on.

My proposed solution is to install a refurbished Bosch alternator. I believe the wiring is all correct for me to swap it in as long as I match the wiring schematic posted above.

Does anyone see any flaws in this logic/approach?