Rory I was looking and it looked like I would need what KMcCallah was showing with the regulator. I would rather not do that do you have a part number for the proper alternator. I looked up 95 mustang and it looks not right.
No, you don't. You can scarf either part of the harness out of the donor vehicle or buy the pigtail online. The red/green "exciter" wire that tell the internal regulator Key On is the same color in the 90's cars. Yes - Ford used the same color wire for that connection over 30 years. Yellow is "sense" and on an older car goes to the same post on the solenoid as the main power out. It's a load sensing input for the regulator. Then just the big power wire, 8 gauge at least. On the 93 F-350 I used a 90A breaker in between the alternator and the battery just for extra safety since the truck has big demands from lights, trailer lights, AC, ignition, etc.
On the race car, the main power goes back to the battery in the trunk, the red/green from ignition on, yellow to main battery power connection on the power distribution panel.
Also - most of the 3Gs I've scarfed use a 10mm bolt in the adjuster boss. I just drill/tap that to 3/8. Around here, most yards have one or two shipping containers that they pile alternators in. So you can just sort through the piles pretty easy. Last one I bought was $45. And if you care, all the main line auto places will test the unit for free. Also note these come in "small case" and "large case". I usually have to put a thin shim on the shaft for a v-belt pully to make it work on a 3G 6 rib style unit. Alternately, you could mill maybe .050 or so off the face of a 3G around the front bearing boss.
