Re: John's 41 120 Convertible

Posted by HH56 On 2019/5/13 14:36:33

If it was an accidental swap done by someone that didn't know Packards were positive ground, I doubt if any of the regular items that change when polarity is intentionally swapped was touched in the car. Battery cable being hot is not a good sign so hopefully a new 0 or 00 gauge cable will take care of that. If not about the only other thing that will cause a draw heavy enough to make the cable that hot is a poor connection or starter in need of some work.

Unless something was changed to a solid state replacement -- about all that would be affected in that car is a radio vibrator -- nothing else in a stock car should have been damaged by the polarity reversal. The voltage regulator has been a question of what exactly the difference in construction is between a regulator designated positive or negative ground and one that is designated universal. Keep that item in mind if repolarizing doesn't do anything. Batteries also have been damaged but those seem to be only if the reversal has been long term and the generator was never charging or was actually working but charging and supplying a significant current of reverse polarity during that time.

Since it doesn't appear to be charging now I would put the battery back to normal polarity and repolarize the generator and go from there. If ammeter starts indicating a charge then all is well. If it reads backwards or no charge is evident then possibly the ammeter leads were swapped or the generator/regulator is not working.

Aside from the ammeter, the other item that should be changed for a deliberate swap is the coil polarity. If the car has the armored cable the coil probably was not touched but if both coil terminals are accessible then make sure the distributor is connected to the terminal that reflects the ground - positive in this case.