1950's Delco 12 Volt Generator-Standard Ignition Voltage Regulator (2 months old). Regulator is correct for this Generator, I have an independent auto parts, Franks Auto Supply, he's an older guy, a hot rodder still and knows his shit. He said this was a "type A" circuit Gen and got me the proper Reg for it. Generator was checked out at a good auto electric shop and got a clean bill of health. It's only making 12.68 at the cables no matter the rpm. If it sits for 2-3 days I have enough juice to start it but on a short 1-2 mile ride to the store, shut it off and no juice to start it back up. I pulled the battery cable while it was shut off, put a test light from the cable to the terminal and it won't light so I'm pretty certain there is nothing drawing the battery down when not running. I have a facet electric fuel pump also, pulled the fuse for that and checked volts at cables while running, same 12.68 Turned the headlights on, same thing, 12.68. I figure the generator should make 13.5-14 volts and 12.68 or so just isn't enough to replenish the battery and have any reserve. The only circuits I run on the truck are the ignition, the fuel pump and the head and tail lights. Bare bones. No radio, cigarette lighter, nothing. All of this diagnosis was done with a freshly charged battery at 13.2 volts and the generator properly polarized. So, my question is, can I adjust this regulator here at home and just keep checking it at the cables with my volt meter until it's where I want it? Or pull the Gen/Reg and have the auto electric shop do it?