alternators: 10si vs 12si wiring
 

I know this has been covered extensively however, I've have been looking and am still a little fuzzy.
I'm looking to upgrade from an externally regulated 10dn to an internally regulated unit.
Looks like 10si alternator can be installed with a jumper wire at the regulator and a plug swap at the alternator.
https://i.ebayimg.com/images/g/BLIAA...hJ6W/s-l64.jpg
When I lookup 12si conversion:
Some claim you can install a 12si with the same simple mod.
Some say you need to cut into the harness.
http://i.imgur.com/hHiWxdE.jpg
...Or am I reading that wrong?
does a 12si wire up the same as a 10si?

I don't need more amps than a 10si will provide and I don't want to chop into my harness right now.
That being said, If I can install a 12si without rewiring, obviously I will.

Thanks,
-Russ

Re: alternators: 10si vs 12si wiring
 

I swapped a 12si in place of a 10si on my 75 C10. Drop in replacement. No changes needed. I did it because the 12si puts out a few more amps at idle speed and largely gets rid of the dim down effect when you stop while headlights, blower motor and wipers are all running. Like you, I didn't need the increased max output.

Re: alternators: 10si vs 12si wiring
 

Decided to go with 63 amp 10si, it just looks correcter.
Guess I'm going to do a quick rewire while I'm in there too. I wanted to avoid opening up the wiring harness, but my CDO [properly alphabetized] won't let me leave jumper wires under the hood.

Re: alternators: 10si vs 12si wiring
 

You should read my thread in the electrical forum stickies on frequently asked questions. It contains a lot of info on converting to internally regulated alternators.
I think you are telling us you are OCD not CDO but I could be wrong. VV

Re: alternators: 10si vs 12si wiring
 

I found that sticky after I posted this, thanks for all the information.
I got it done and am happy with the results. The wiring defiantly needed some attention.Attachment 2093541