Packard Forum Index » V-8 (1955-56)

The only obvious way I know of to determine ground is to look at battery. If pos post goes to ground and negative to starter solenoid, it is correct. The generator does not care since it has no solid state components. The generator and regulator can be re-polarized to proper orientation just by momentarily shorting the bat & gen terminals together on regulator. This "magnetizes" the armature and field coils properly--just like when you were a kid in science class and made electromagnets from nails (if they still do that nowdays).

While they may be built and possibly may be more efficient at a specific polarity since some catalogs do show a polarity, I believe the various numbers on generators and regulators have more to do with construction details and how many volts and amps at how many revolutions & temperature the generator will put out and regulator will try to maintain. Evidence that by the number of people who have changed polarity either intentionally or accidentally, yet changed nothing else and had no issues. (Of course, other things in car would change but not gen/reg.)

I forgot to mention that the guy who sold the car to me took out the battery when he left and he insisted that it was negative ground as I stated at the top of this conversation. How much would it hurt if, when I put the new battery in, that I try it on positive ground?
The wire closest to the front of the car is grounded.
Thanks again guy!
55clipperguy

If you have a stock Clipper, there is nothing that would be damaged by putting the battery in as it should be.

The questions that need to be answered:

was it changed to negative ground for a specific reason such as did the previous owner have a radio, tape, or some such which needed neg ground and is now gone.

because someone didn't know better

and finally, was one of the solid state replacement components used somewhere while it was negative. You need to verify if anything solid state such as torsion level control or radio vibrator or things like that has been installed because those will be damaged.

If a car is changed from positive to negative ground, there are several things that need to be changed. Check these things, they may tell you if the car was changed over at some time or if somebody put the battery in backward by accident.

The wires on the coil should be changed. Normally the + would connect to the distributor and the - to the key. If it is the other way around the wiring has been changed.

If there is an ammeter the wires need to be switched as well. Otherwise the ammeter will read "backwards" showing a discharge when running and a charge when you turn on the headlights etc.

The generator would need to be polarised. It is hard to tell if this has been done unless you use a meter.

Incidentally if the battery was accidentally put in backwards, it is possible to charge it backwards, turning the + side to - and the - side to +.

I know someone who did this years ago. He had a + ground Triumph TR3 which he put the battery in backwards and went for a long drive. The car started and ran normally and when he got home, the battery was charged backwards.

This takes a lot out of the life of the battery. If you try to reverse the charge again, in other words change it back, it will ruin the battery completely.