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I have a 1936 120 with the GBR Autolite Generator. The ammeter seems to stay pegged at 30A once the car is past idling. One person told me this is normal, that the device on top of the generator is an 'interrupter' not a regulator, and that it's only purpose is to stop current from flowing back into the generator when the car is turned off to prevent it from 'motoring'. The manual seems to indicate that it is a regulator. I'd appreciate any info on whether I have an interrupter or a regulator, and if it's an interrupter if there is something I can do to prevent overcharging (by adding a regulator?), and if it's a regulator, whether staying pegged at 30A indicates it may not be working correctly.

The 1935 "120" still used a 3rd brush generator, unsure of Auto-Lite in 1936 but if you have a 3rd brush generator, you adjust your maximum charging rate by rotating the 3rd brush via a screw on the rear of the generator. Drivers of the era often drove with the headlights on it the daytime to prevent overcharging of the battery because it was easier to do than to stop, open the hood, and adjust the 3rd brush. I do that myself occasionally in my 34 with 3rd brush adjustment. I set mine so that at road speed with the headlights on I am just barely on the positive side by a couple of amps. For 99.99% of my driving that's fine - it's just prolonged daytime trips that I may turn the headlights on or turn the 3rd brush down a bit. Pretty simple basic stuff of the era (not unique to Packard), I believe it's also covered in the 36 "120" shop manual. I suspect if you search this site for "3rd brush generator" you should find plenty of discussion.

Assuming for the moment the 1936 120 used a 3rd brush generator as did the 1935 model, then the comments about the regulator being a "cut out" is more-or-less correct, though I've never heard it called an interrupter. It does incorporate a primitive voltage control but no amperage control based on system demand and does indeed disconnect (interrupt) the connection between the generator and the battery when the generator output has dropped below the battery voltage, as when the engine is shut off.

PS - Looking thru the A.E.A. catalog, the 1936 "120" still used a 3rd brush generator (GAR 4611A or GBR4611) and a simple cutout and voltage control TC4302A. So the answer is, turn down the 3rd brush to give less output, assuming that's what you want.

How about a picture of the set up Doug???

Look at the FIELD post on the generator. If it has a wire connected from that post to the generator frame then most likely it has been gerry rigged for full blast output.

G'day Doug,
See you've been a PackardInfo member for a while, but first post, so

Can't help with your query but have a request of my own. Could you please include your '36 120B in the Packard Owners Registry here on PackardInfo?

Thanks everybody.

The car has an Autolite 3rd brush generator which I was able to adjust using the instructions in the 1935 Packard 120 Shop Manual (available on this site, pg. 36), by removing the covering strap and pushing the brush in either direction.

The ammeter behavior is now more reasonable - peaks at a little over 20A and backs off to just charging with the headlights on after the car has warmed up.

I have added the car to the Packard Owner's Registry.

The attached photo was taken by a prior owner in front of the Packard Building in Philadelphia, PA, which was originally a dealership and is now luxury apartments.

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Doug,
for including your '36 One Twenty Business Coupe in the Registry. Love the picture.