Alternator (Lima) 0 120 400 606 K1 14 V 35 A why extra long M5 bolt sticking out

Hi Gents,

Recently i put new bearings and carbon brushes in my old alternator Bosch 0 120 400 606 K1 14 V 35 A.
The housing is build up of two parts and connected with 3 M5 bolts. But why is bolt n3 3 extra long and sticking out of the housing?

My guess is that it is sticking out so people can make an extra earth connection, when the earth connection is not going well via the motor bracket?

Looking forward to hear any thoughts about this mistery bolt.

Greetins Marc

 

Yes, Marc, it is exactly as you think.
The alternator normally is mounted by rubber-elements and need a separate ground-wire.
This is mounted by ring-connectors at the 'long bolt' and one of the screws of the console.
Often a condensator against electrical disturbances in the radio is also mounted at the bolt.

Regards
Norbert

Thank you Norbert,

I was triggered by this website, see the picture at the bottom of the site.
www.strichacht-forum.de/knowhow-v2/index...ren_Anschl%C3%BCssen

There is shown the earth cable nr E. See below.
I have no clue where the end of this cable is attached too exactly (which frame part) in my W114 250 CE

ps My Alternator has no rubber elements between the housing and its bracket that is connected to the motorhousing.

Greetings Marc

 

Hi Marc,
if you don't have isolating rubber-elements, you don't need the wire.

For a higher security (maybe there could be corrosion) you could connect the ground wire to any bolt of the engine, but not to the chassis.

The wire is not strong enough to withstand the extremely high current during the starters operation, if the main ground wire from chassis to engine is defective.

You did right to rebuild the original alternator.
The cheap alternatives are often reported to be of low quality.

Regards
Norbert