I have installed a 409/425 h.p. engine in my '58 Chevy Impala convertible. My question is, can one or some of you electrical "gearheads" out there, tell me if I can some way use my original wiring that hooks to the generator, to also use to hook-up an alternator for the '09? If so, could you try and guide me through the hook-up? I would much appreciate it. I was considering putting on a "single wire" alternator, but I have been reading about what some of you guys have said about them. Seems that most of you are not in favor of them. So I guess I have decided not to take the SO-CALLED easy way of the "single wire". Age old story, if it sounds too good to be true, it usally is. Thanks in advance, 1958impala
I think you basically have a wire coming from the interior through the firewall and connected to the Horn Relay Bus bar (common tie point). Also there is a wire running from the starter to this Bus bar, that is connected to the main battery cable. So, run your alternator Bat wire to the Horn Relay Bus bar as well. The voltage regulator should have three terminals on it, with two of the terminals wired directly to the generator (field and armature), and the other wired to the Bus bar (Bat). As you can see, none of them are needed, so just remove the regulator and be done with it. On the 3-wire alternator, you have a clip that has a #10 wire and a #12 wire. Fold the red #10 wire over and connect it to the Bat terminal of the alternator. This is called the Sense wire, and if you have a lot of electrical options (seats, windows, electric antenna, air conditioning, etc), then you should really run it in parallel with the Bat wire to the Horn Relay Bus, which provides a better sense point. The last wire on the alternator is called the Exciter wire. This is run all the way to the ignition switch. You can put a diode in this line (stripe towards the alternator) or an idiot light. Either will cause a voltage drop, and allow the alternator to start charging. Go to the Painless Wiring web site and download any of their manuals. They will have the diode shown and the radio shack part number, as well as wiring ideas.
On a couple that I've done using a one wire alternator, I've torn the guts out of the regulator and used it as a "junction box". Connect the "Bat", "Fld" and "Gen" terminals together inside the regulator, then at the one wire alternator connect both the Gen and Fld wires to the big stud on the back, and you're good to go. No new wires to run, and it still looks kinda like you're using the old regulator. That said, I don't normally run one-wire units, as I like to use the remote voltage sense and "idiot light" terminals for their intended purpose.
The Jalopy Journal
