Alternator Wire 280SL

[TJMart]

Is the alternator wire on my 1970 280SL in the attached photo (green) the ground wire? If so it appears that wire was re made and installed. Is this the right wire and is it the correct color and gauge? As a side note where can I get the wire boot and how should the wires be re - wrapped?

[Pawel66]

I am not an expert and I may be reading the picture wrong, but if these are two thick wires joint together and tightened with the nut: they are permanent + wires from the battery that used to be red years ago.

I would replace them ASAP.

Gauge: 4 square milimeters (you can give a bit more).
Color: red.

If they seem stiff it means insulation will crack rather sooner than later. A big fire guaranteed, they are not fused.

Sorry if I am causing unnecessary panic by reading the picture wrong.

[Shvegel]

red wires are cloth over plastic.  They are just shedding their cloth.  Pretty sure the alternator grounds through the bracket regardless that wire isn't sized to carry the full charging amps. 

Search term "Bosch Alternator boot" 
https://www.autohausaz.com/pn/3130558000?utm_source=google&utm_medium=cpc&utm_campaign=frooglePN&utm_term=3130558000&gclid=Cj0KCQjw28T8BRDbARIsAEOMBcyttwIKt_K1V8vYA4ytI8ynMrLjMoqWzRyXZqWgn2E7Mh5nrngw-x4aAme3EALw_wcB

[Benz Dr.]

Looks like an extra ground wire to me.

[lpeterssen]

Dear friends

I agree with Mr. Benz, the green thin cable with yellow terminal looks like an extra ground wire.  If worried about originality change it for a brown cable and use terminals not colored. As is a ground terminal does not need insulation.

Regarding the two main charging cables which are cloth over plastic wall insulation, only on certain years, the newer ones...  I have seen so many cables of this kind in bad shape that I would suggest at least to change the segment from the alternator T30 terminal to the same terminal in the starter.   That is the critical segment which is most frequently compromised in all cars I have repaired their wiring harnesses.

Size /gauge as indicated by PAWEL. Having a thicker wire will not hurt anybody, not even your car.

Right color = RED, SUGGESTED SIZE in order to have only one conductor instead of two = AWG8 which gives you 12 mm2 of cross section.  You have at the moment two conductors each 4mm2 totaling 8mm2.

Best regards
LPETERSSEN

[TJMart]

Thanks everyone for the excellent advice!

So would it still be ok if I just remove the green extra ground wire?

Just to make sure I understand, if I use a single AWG8 wire to replace the 2 frayed ones that will achieve as good or better result?

[lpeterssen]

Thanks everyone for the excellent advice!

So would it still be ok if I just remove the green extra ground wire?

Just to make sure I understand, if I use a single AWG8 wire to replace the 2 frayed ones that will achieve as good or better result?

The AWG 8 wire has a greater cross section than your actual configuration. So it will perform better you will observe faster charging rates on your battery as that bottle neck is eliminated.  You will have 12mm2 cross section against ns 8 mm2 original (2 times 4mm2).

The green cable can be eliminated without doubt if you have an internal regulated alternator. But ..... if you still have an alternator that has one major connector for the T30 cable and three secondary small cables  (N one multiple connector) then I will not eliminate that extra ground, since may have been installed as a result of a defective connection on your harness going to the external regulator.

Best regards
Lpeterssen