So I read quite a bit about doing this and I am documenting for others what worked for me because it is a real $@^-#! trying to figure this out by yourself and while there is a LOT of info on the web, not all of it is useful or correct. I decided to use the Chevy 10Si self regulating Alternator due to it's availability/cost and performance. I also really didn't want to have to mess with updating the 3 wire voltage regulator to a 4 wire, messing with harness more than necessary etc.
I almost went down the "one wire" alternator route but many online talked me out of that. It really is for tractors. It is only a battery charger. It isn't meant to run a whole electrical system and it can't regulate downfield to keep up with voltage drops. The "self exciting" thing is weird on those too. You need some RPMs to switch them on. (YUK)
I have machine shop access so for me, the bracket was easy, but they are sold online if you search. I took pictures of my bracket design. The bottom alternator flange is 0.200" wide so my brackets fit that closely then tighten right up. The alternator needs to go up about 1" and over about 2" and out about 1.5" in order to mount. Swing the top bracket down and your new bracket should be inline "Z" with that bracket so your alternator isn't tipped up or down but straight. I saw others messing with the top bracket too, buying curved top brackets for alternator, but my straight top bracket worked PERFECTLY. (perhaps they had different alternators) or my bottom bracket is just purrrrrrfect? Oh.... check the clocking when you buy the alternator. My Nappa part#213-4010, the wires exit on the right side and the clocking is correct. It is a 50 amp alternator. I have a all stock 62 Comet with 170. I have NO extra accessories, racing fans etc... so unless you do, you don't need a high amp alternator and those extra amps may be dangerous some day if things go wrong.
The wiring was the hard part for me.
WIRING Diagram image is below but here is WIRING Description in words:
Remove Pos and negative battery cable and battery. remove 3 wires from generator. Remove the generator (duh)..... The large (10 gauge yellow/blk stripe is voltage out from the back of the generator and this will go to the back BAT post (output) on the Chevy Si alternator. You can buy a 2 connector pigtail for the alternators for 3$. One wire red, this is the "sense" wire. The other is white and that goes to your ignition/key on through a diode to prevent reverse flow.
Now the other 2 smaller generator wires.... you can leave both disconnected/wrapped and hidden. the smaller blk/yellow wire was the "F" wire on generator. The "G" (small blk/red was ground at the regulator. You don't need this either. The alternator is grounded and the VR is no longer used. Now You run some 16 gauge white wire from that white chevy pigtail (through a diode) and out to where that small field wire used to go. The white stripe on that diode goes toward alternator for correct flow. Then from the other side of that diode you run that new white wire along the old harness up over the radiator (hidden) and to the VR area. This is your "excite wire" that goes to ignition on. (more below)
The red "sense" wire sense voltage downstream WHEREVER you want to connect it. Many people online show it jumped right from the pigtail straight to the back of the alternator output. That is kind of dumb as the internal regulator will only see the voltage "AT" the post, rather than down stream or at least at the battery for gods sake.
The voltage regulator is where things got real fuzzy for me.... not a lot of info and I read threads long and hard until someone on a thunderbird page got me close. Long story short, you want to remove the smaller 18 gauge yellow/blk wire from the "A" terminal. (ignition key) and that now goes back up into the harness to the newly run white GM pigtail/diode etc. Next jump the "A" terminal large 10 gauge wire directly to the "Bat" terminal wires. You disconnect the small "F" terminal field wire and wrap it up and hide it. My wires are in excellent shape but if yours are not, consider running a new 10 gauge output wire out of the alternator rather than using what is there. I tried it and it worked!
Now (for me anyway) to make things look a little more stock and clean, my idea was to leave the voltage regulator in place for looks and to use it as a junction connector for adding a fusible link. I gutted the insides. I removed ALL connections, front and back, all the resistors on the back, all coil windings, and regulator parts that I could tear out. I ohmed it out to ground/body and to each terminal to make sure there was no connection either to each other or ground/reg body. (All floating) Then rather than jump the large "A" wire (output from alternator) to the 3 "Bat" wires, I connected the old "A" wire right where it was (at the bottom) and put back all 3 "Bat" wires (crimped together factory) where they were on "Bat" terminal and made my connection from one to the other via a fuseable link (14 gauge) which is a good idea to protect from shorts and burning up your system. I bought 2 extras to keep in the car for any trouble. It is a nice easy place to access if you are ever stuck on the road...... a flat blade screw driver later, you are good.
The end result is that voltage at the battery while running is held at 14.2V with nothing on. Rev the RPMs, no change. Now when I turned EVERYTHING on, all of those 1962 luxury items like lights, blower fan, AND a radio, (wipers are vacuum) it reads 13.8 at the battery. Pretty Sweet! Now if you do have accessories, this is where running that red GM "sense" wire farther out upstream to a junction would help to keep voltage higher by "sensing" the drop upstream rather than the battery but for my little ride, it is great as is. I really didn't want to have to run and try to hide another larger red wire
My dash lights were noticeably brighter so I dimmed them down a bit on the knob,
I hope this helps. Finding info can be hard and I wanted to help give back to this place!
