QuestionHi Brad, I`m still working with the wiring harness issue with my 1938 Chevrolet, the harness problem solved, I purchased one. The next problem is with the voltage regulator availability. The car originally had a four terminal firewall mounted regulator, from what I`ve seen on the detailed wiring diagram I have, there is an internal coil and points that handle the cutout, those terminals being G for generator, and B for battery. The second coil and set of points have two terminals, on one side, the F terminal, for generator field, and the other, S, for ingnition switch. I`ve checked every reproduction parts source I know of, and none of them offer the original four terminal voltage regulator, although they do list three terminal models, for later year model Chevrolets. I did order through one of the suppliers what I thought was going to be a full voltage regulator, but turned out to be a generator mounted "cutout" only. My generator has no mounting holes for this type of cutout, and I`ve learned earlier years used this type of cutout, but `38 used the four terminal firewall mount unit. Do you know of any possible source of a reproduction, or even an NOS regulator, or can you further advise me with this problem? I`ve called various suppliers, as well as the wiring harness manufacturer, and they don`t have any further advice. I`d prefer to use an original type regulator, but I`m not totally against a minor rewiring situation, but I don`t have the credible knowledge to assure I wouldn`t be making severe mistakes. Any advice you can offer would be most appreciated Brad! Thanks, Dave P.S., on an unrelated subject, the gasoline issue. I`ve read opinions in either direction, that unleaded gas would not be harmful to the original 216 babbit beater, and others highly recommending the lead additive. The engine I have is a rebuilt (in 1973) original with approximately 3,000 miles on it, which I pulled out of my first `38 Chev before I sold it. It is in this current project car, and has not been started since 1979, but has always been stored indoors, and I "pickled" it after I pulled it. I would like to be sure I`m taking every available precaution so as to prevent damage, as even in 1973, the rebuild cost me $1,300, and I`ve seen where todays cost to re-pour the babbit bearings and line bore a rebuild, is extremely costly. Thanks again Brad, for both your expertise, and your dedication to the old car hobby (addiction) through the "All-Experts" site!
AnswerWell, here is what the skinny is on your voltage regulator issue. The system that you have on your car is a two year only, 1938/1939, system. It was the first attempt by GM to update the old three brush generator. The current cut out that you mentioned was used only with the three brush early system where the third brush was adjustable to control voltage output. In 38 GM came out with a three brush generator where the third brush was fixed, not adjustable, and a two coil four terminal regulator. In 1940 this system was replaced with a two brush generator and a three coil regulator. Now I checked my usual list of suspects (suppliers) and no one that I checked with has any knowledge of a source for the 4 wire regulator. Now here is where being an old guy has its advantages. I started working as a mechanic in 1948. In that time frame we were routinely removing the old 4 wire regulator/generator set up and replacing them with the 3 wire two brush generators. The wiring to make this work is simple. The generator, battery, and field wires are connected as with the old system and the only thing different is that the ignition switch wire is folded over and taped off. Now on the gasoline, I have been running my old cars and tractors on unleaded gasoline since it was introduced in 1975 with no, repeat, no problems with valves or any thing else. I won’t comment on the problems with the ethanol in the new fuel though.
Good luck, Brad
