As I am driving down Saturday to try and get my 1950 5703 COE running, I had better find how what voltage the electrical system is and whether or not it is negative or positive ground. How could I find out if the previous owner upgraded the electrical system. There is no battery in the truck. The goal of getting it running (was a year ago) is to load it on and off the trailer rather than winching it up.
You could check the generator/alternator for any nameplate, it should show voltage or a model number. Also see if there are any add-on gages that would indicate someone making modifications to the electrical.
1957 Chevrolet 5700 LCF 283 SM420 2 speed rear, 1955 IH 300U T/A, 1978 Corvette 350 auto, 1978 Yamaha DT175, 1999 Harley Davidson Softail Fat Boy
Chevys during that time period were 6 volt negative ground. If it was upgraded to 12 volts, there should be either a ballast resister feeding the coil or a coil that does not need a resister. The coil should be marked either 6 or 12 volts and if a resister is needed.
Phil Moderator, The Engine Shop, Interiors and Project Journals
1952 Chevrolet 3100, Three on the Tree, 4:11 torque tube Updated to: ‘59 235 w/hydraulic lifters, 12v w/alternator, HEI, PCV and Power front Disc Brakes Project Journals Stovebolt Gallery Forum
Another good indicator for deciding if 6V or 12V "generator" (if you can't read whats on the tag itself) - What color is the tag? Black tags were 6V. and red tags were 12V.
If it has an alternator and not a generator, could still be either or, but most likely 12V. Rating will be stamped into the housing somewhere.
Let us know what you discover.
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
There will be no need whatsoever to have the charging system in operation for a short run. Disconnect the wires from the generator and regulator, and simply run temporary wiring to the ignition system. A well-charged battery will get the engine started and run it for several hours on nothing but battery power. I'd suggest running a new 12 volt coil and battery if all you intend to do is run the engine long enough to load the vehicle on a trailer. Use a ballast resistor between the battery and the coil if you choose, or just let the points carry the full voltage if you're only planning to run the engine for a few minutes. Jerry
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All of the six volt Delco generator that I have seen have a band around where the brushes are. The twelve volt ones that I have seen do not. The original 6V Delco regulators have two screws in the top in diagonal corners. The 12 V ones have the cover screws , one on each side at the edge of the lower edge.
Hotrod's suggestion will give you the very best chance of success. Also when I am waking up an old engine, I like to power the coil from a separate source so the voltage doesn't get dragged down by the starter draw.
All of the six volt Delco generator that I have seen have a band around where the brushes are.
I have a six volt Delco generator that has no band around it, but has a stepped down rear case. But it's not original to the truck. It has "Wizard" stamped on it so it's likely a Western Auto rebuild. So that's not a definite way to tell the generator voltage.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
