Packard Forum Index » Post-War (1946-54)

1947 Custom. After starting, ammeter stays in middle, but shows discharge if turn on lights. After several miles, usually goes to full charging until shut down.

My other cars always go to full charging after juice used in starting, then gradually drop to mid range.

Do I have a problem?

Would be interested to know what your voltage is whilst it is charging. Am at a bit of a loss as to why the charging does not start as soon as the engine revs come up but fair to say dirty connections are often the culprit. A dirty commutator or weak brush springs also come to mind.

Remove your fan belt and take the sheet metal band off the back of the generator. Poke a piece of scotchbrite in onto the commutator and then spin the genny by hand till the copper is bright.

Ross, neat trick. We used to use a soapstone to finish the commutators after overhaul assembly to help the brushes seat.

Assuming the battery and gauge are good, and it's actually not "overcharging"(boiling), then either it's not getting high enough voltage to charge, the contact for the "shutoff" coil is non-functioning - or both. Disconnect the battery and take the cover off the VR and inspect the contacts.
Like Ross said need to measure the voltage when it's charging.
I would suspect over time after several such episodes the battery would discharge and not start. Must be a new battery. I like to install a voltmeter in all my generator cars to aid diagnosis. Those charge/discharge gauges work off current flow and don't tell much about system health. They're more for "show".
Any auto electric shop should be able to diagnose and fix this
rather inexpensively, if not swavvy or DIY.