Performance of original charging system — D25

[bamfordsgarage]

I recently rebuilt the roof rack on my '47 D25, which with mission creep, entailed going through not only the rack lighting (signal, marker and hit brake light), but replacing the long-dead second battery and cleaning up various connections throughout the charging and lighting circuits. The generator got new brushes a few years ago; the regulator was set up by an independent auto electric shop around the same time.

 

All is functioning well now, and some readers might be interested in the real-world performance of this factory charging system...

 

Photos were taken yesterday evening, with the following electrical loads:

— headlamps on high beams (H6006 halogen 6-volt)

— two heater fans on full (the factory heater and a second, identical, heater installed 10 years ago prior to an Arctic road trip)

— four marker lights (front greens are visible, red rears were obstructed)

 

The ammeter showed discharge at idle of course, but reached 'cross-over" at about 1,00 rpm and positive charge at higher speeds.

 

I find this very satisfactory — even with the additional non-factory loads the generator keeps up at 20 mph or faster. No inclination here for an alternator or 12-volt system (no 12-volt loads either!) 

 

The second battery was installed 11 years ago in parallel with the factory battery as a reserve for camping and longer road trips. It can be isolated as needed.

 

 

 

[sidevalvepete]

Thanks for posting. Interesting information. I have added heater, radio, clock, fog lights and indicators to my 1938 version and will replicate what you have done here to see how it performs when the rebuild is completed. Have also stayed original 6volt system.

[Dodgeb4ya]

I also have never had any serious charging problems with any of my flathead MoPars.

The regulators on a couple cars have been replaced with factory Autolite regulators.

These generators charge fine when good quality or OE parts are installed.

[greg g]

Never had an issue with my car either.  Biggest things I did was run head lamp grounds to a better spot, put on a body ground strap, and re powered the brake light switch  with a dedicated fused feed.  Running three brake lights at 55 watts, and 35 watt 2x for running lights.  Its funny, with it wired as it is now, instead of discharging with headlights and brakes on, the regulator senses the load pops the field on and my gauge goes to positive on low beams at least.