[pinshaw]

Need a little help with wiring back the alternator. Think I have most if it right
think grey wire goes to oil
filter if i remember right
lmk if it looks right to you
thanks

 

[alfaparticle]

I am pretty sure that your car originally had an external voltage regulator that connected to the alternator by way of a 3 or 4 pin connector. There are posts about replacing the original alternator with one with a built in regulator which just has a power terminal and an excitation terminal. In that case the wiring is similar to a later model Spider.

 

[pinshaw]

Youre right. Im trying to put it back the way I got it, ext vr n all. We’ll see how it all works then.

 

[Andrew]

US 69s often had this setup, no three-pin plastic connector. I think it's the same regulator that the later alternators use, but the connections were not ganged onto a plug at the alternator end. I think this is original.
Andrew

 

[Alfajay]

US 69s often had this setup, no three-pin plastic connector. I think it's the same regulator that the later alternators use, but the connections were not ganged onto a plug at the alternator end. I think this is original.

Yes. Both '69's and '71's had separate wires at the alternator, but the 3-pin connector at the regulator. And yes, it's the same regulator as on the early 2L's. So pinshaw's alternator is definitely original.

But I guess his question is: Do the wire colors look right for the green, black and brown wires? Beats me; I converted my cars to internally-regulated alternators some time ago. One tiny bit of help: Yes, the grey wire goes to the oil pressure warning light switch.

 

[pinshaw]

Ill take the gray wire, thanks
OK, lets simplify this, is the wire from the black boxy part connected correctly on same connection as the blk (ground?) wire?

 

[Alfajay]

OK, lets simplify this, is the wire from the black boxy part connected correctly on same connection as the blk (ground?) wire?

My guess would be no. I also don't think that the black wire from the regulator is a ground (typically ground wires are brown on an Alfa).

My guess is that the "black boxy part" is simply a capacitor to suppress RF noise coming out of the alternator into the big, red wire. The noise suppressor is grounded by it's mounting screw and its black wire goes on the same stud as the big red wire. You might wait until someone else confirms this, but I'm 98% sure that is right.

Alternatively, leave "black boxy part" unconnected and see what happens. My guess is that everything will work fine, except that your radio will buzz at a frequency that goes up/down with engine rpms.

 

[goats]

71 spider

 

[pinshaw]

Thank u, this all helps.
Appreciate it