Packard Forum Index » V-8 (1955-56)

A prior "restoration /preservation had converted the 6 volt system to 12 volts. I beleive the car sat for around 12 years with no significant driving other than to start and run briefly. Still working thru some glitches in electrical...fuel gauge, radio etc but most of the electrical systems are working fine. After driving several trips of 30-50 miles round trip, I realized the generator is not charging the battery. I believe I saw a reference to the conversion issues that might arise but can't find that thread. Any suggestions as to where to start trouble shooting the wiring from generator?

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55-56 cars were always 12v but while 55 kept the old positive ground 56 finally changed to negative ground. If your 55 is now running a negative ground and the generator was never repolarized for that change it is possible that could be the reason it is not charging.

Presuming it still has a generator and that was not changed out to an alternator during any conversion work it would not hurt to give a repolarizing a try. It may not help but done correctly, it will not hurt anything either.

To repolarize, get a short piece of decent size wire -- about 14ga will do. With key off and everything else connected as usual use the piece of wire to BRIEFLY short the BAT and ARM terminals together at the regulator. The FLD terminal must not be shorted in this procedure so make sure you are working with the BAT and ARM terminals only. A quick 2 second or so connection is all it takes to magnetically polarize the field coil pole pieces in the generator so that when the engine starts a small voltage will be produced that is enough to bring in the relay that connects the rest of the regulator and charging circuits.

If the battery ground was changed to a negative ground it is OK to leave it that way as nothing that was standard at the time is polarity sensitive -- although some regulators are labeled as positive or negative and it is still a question as to what exactly is different. There are other things that may need to change though. If wire connections were not swapped, the ammeter will read backwards and the coil will not be as efficient if it still has the + terminal going to the distributor and ground. If anything was changed to a modern solid state replacement such as the radio vibrator any solid state items may be damaged.

If the car ground is correct and repolarizing did not help then another test can be done using the FLD terminal to try and isolate the problem to the generator or regulator. If you need to do that test you will need a voltmeter and the short piece of wire.

Thqnk you Howard...brain Phart on my end re 6-12 volt vs Pos-Neg ground. The ground was indeed changed to Negative while my 47 retains the positive ground (note to self...pay attention:)
Will give that a try.
Cheers
Bob

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Either that or it is still positive ground but the battery was installed incorrectly! That seems the most likely scenario to me.

I would definitely polarize the generator to whatever polarity the battery is now.

The generator might be currently polarized the other way, or it might not have polarity at all. The residual magnetism stored in the field coil pole pieces that gives the generator polarity slowly decays over time (years) while the generator sits unused. The generator needs this residual magnetism to start up. Polarizing restores it.

You can polarize the generator by pushing the cutout relay closed, too. It does the same thing as the jumper wire.