39 Packard Generator and Regulator

Posted by jwblazek On 2019/4/1 11:33:10

Since my 39 Six has a rare option, the mechanical tach takeoff from the rear of the generator, thought it would be wise to rebuild. Opened it up, tons of grease and two brushes severely worn, but no commutator damage. Replaced the 3 brushes, replaced the front bearing and rear bushing and had the commutator tested, all good. Put it all together and apart from some minor sparking at brushes (I'm attributing to new brushes seating), worked great.

Then started replacing wires to generator and regulator as they were badly fraying (original wiring) and replaced with modern cloth covered vinyl wire. Went for a long ride, worked great

Started the car yesterday and a loud buzzing frion the regulator. Noticed ammeter showing heavy discharge so shut off. Repolarized generator and seemed to work OK. After another drive, same problem.
Pulled cover off a NOS regulator I bought about 9 months ago and saw that the points to the geberator field had overheated. Replced regulator with the old regulator I had that had issues of overcharging as a troubleshooting aid, and it seemd to work fine. Went on a cruise with a charter group of teh AACA and had huge issues on return leg of trip, heavy discharge

I am suspecting an intermittent field winding causing teh polarity to get reversed as it wouyld do if disconnected from circuit

Looking at the schematic in the service manual confuses me. It says car should have a VRD regulator, this one is a VRR, as was the onbe I pulled out. Generator is a 3 brush GCJ-4810A-2 which is correct

Car had run for years with this config, possibly as long as we have owned it so looking for suggestions. Fou0nd another NOS regulator which should arrive this week but reluctant to connect as they will get ruied if field polarity is reversed

Suggestion? Correct schematic anyone?