Packard Forum Index » V-8 (1955-56)

Keep us posted on your progress.
One thing to keep in mind is that "GM alternator" is simply not specific enuf make a long term decision. Which ever "GM ALTERNATOR" u decide on be sure to determine the SPECIFIC make model and year of GM product that the alternator was originaly intended for. THat way u KNOW what u have.

LEt me put it another way, JUst try walking into aprts store and ask for a "GM alternator". I doubt that u will get very far.

My specific recommendation, if i were converting to alternator would be to ask for 73 Chevy Caprice alternator or maybe 89 Caprice or maybe POlice version of either one of those two. Others mite have a better SPECIFIC make model and yhear recommendation. Try to avoid Cadillac simply due to cost issues. Just some research u need to do along those lines. The Cadillac is most likely same as the Chevy POlice version anyway.

LEt us know what u find out.

What does "self-exciting" mean? Is that the same as a "one wire" unit?



That same alternator site I referenced can give some specifics on various type alternators. Here is what they have to say about self exciting or one wire.http://www.alternatorparts.com/what_is_a_self_exciting_alternator.htm

Try this web site too. IT has an 'other applications' list feature that will list all make, model and year for any given part number (the stores part number).

http://www.oreillyauto.com/site/c/cat/Replacement+Parts/C0001/00000.oap

I'm running the 63amp version of the 10si in my Clipper. This was basically the standard Alternator used in the mid-70s GM products. You can get them "clocked" in various positions so the the wire terminals are on the side you want them on. The also use a fan/pulley which works with the style of belts that Packard uses.

Fairly big subject. There'll be auto-electricians out there in cyberspace that can explain better than me, but here goes . . . .

Basically early car generators had permanent magnetism (their armature was magnetized) incorporated in them at manufacture, so from 'startup' (spin-up) they created voltage immediately, even when car battery was flat. If that permanent magnetic field wasn't present - then no power generated at spinup. These older generators were connected to the old style voltage regulator, with F.A.D.E. terminals (Field, Ammeter, can't remember what 'D' was, and Earth). This regulator had wire-wound relays that cut in / out when the generator was at peak output (otherwise you would fry your battery with 30 volts instead of 13.6V). But they also were responsible for feeding a certain 'regulated' voltage back to the field coils of the generator to provide the extra magnetism needed for maximum efficiency. This is the principle of "self-excitation' where the generator itself provides current from it's output, to provide extra magnetism via electromagnets, rather than just relying on the weaker / less output from the permanent magnet. Therefore a more powerful generator resulted.

With the advent of alternators and solid state rectifiers (with diodes) things changed. The alternator didn't have any permanent magnets in it, and relied on the car battery to energise (excite) the coils for the magnetism needed. Most still had a remotely positioned voltage regulator, so more than one wire went between alternator and regulator. Now with 'single wire' units the regulation is built into the alternator body, so the only wire 'out' is the charge wire.

So, strictly speaking, one wire units have to be self-exciting, but the terminology is not a sweet fit as it is an old concept.

Hope this makes sense. Others might add to it.

I'd say that Kevin just gave the answer we needed.

Nice explanation on the self exciting. One of the reasons for polarizing a generator is to align the residual magnetism. Hadn't heard the F.A.D.E but suspect it was field, ammeter, dynamo and earth or roughly field, bat, gen and ground for our terminology.

Two other things to watch out for on the AC install now that the alternator is suggested. Packard used a relay for their AC feed. Power was thru a fuse straight off the battery connection at solenoid thru the relay to unit. I don't know how others have done it but as those 54-6 ignition switches are reported somewhat marginal on capacity and starting to fail, would suggest a relay and not chance powering the unit thru ign switch. Some of the aftermarket units have a relay built into their loom for that purpose, others do not and just rely on modern wiring systems having adequate capacity. If you chose one with no relay, adding one is cheaper than an ign switch.

The existing wiring between generator and rest of system was sized for 30 amp generators. Couldn't find a spec on 55-56 for the 12v but looking at my car, looks like 12ga. If you find that with AC and headlights on and normal running, the amp meter is always sitting pretty high on the charging side, you might want to keep an eye on that wire for any signs of overheating if you run that way for long periods.