1935 Buick electric help

[eieio94]

I have been having problem with my electric system.  I had generator rebuilt and rechecked several times, but when I add a new voltage regulator, the amps run positive and correctly in the garage...additionally I have a volt meter plugged in and voltage stays between 6.5 and 6.8 even when lights are turned on.  However when I drive the car less than 5 miles down the road, the Amp gauge will suddenly drop to zero and the voltage will start falling off (not charging battery)....I have now been through 3 new voltage regulators.  Does anyone have any suggestions or know someone I may contact regarding this issue?

[JohnD1956]

Once the battery is recharged from the starting procedure, I would expect the amp gauge to drop to 0.  Does the battery fail to turn the engine over at any time?  If not, then the question may be where are you running the volt meter from? If you are running it from the battery then it should read higher than the battery voltage when the system is charging, and the Amp gauge is in the positive ( output) side. But once the battery is charged and the system is in balance ( amp gauge at 0)  the voltage regulator will stop the charging circuit and the battery should return to the 6 volts, maybe a percentage higher.

 

Maybe I misinterpreted your post, but if the battery does not fail, then it appears your system is working as designed.

[Glassesguy]

Agree with John D. Your "amp" guage is really a charge indicator only as per the shop and owners manuals. One the battery is up the needle will drop to zero but may flicker back to + side as the battery needs replenishing.  In 1940 Buick added a current regulator with in the voltage regulator unit which housed the cutout relay and voltage only coil. Now the guage on the instrument panel will function as an ammeter with gradual movements as what most of us are used to viewing.  Someone please correct me if this is not so.

[Joseph P. Indusi]

In my experience, after the engine is started, the ammeter will show a high charging rate and then will taper off to near zero as the battery comes up to near full charge. So showing a low charging curent is normal after the car is run for several minutes at road speed. However, the voltage of the charging system should be near 6.8 volts at this point and not near 6 volts. If you shut off the engine and measure the voltage across the battery terminals you should see around 6.3 volts or more.

How much does the voltage fall off as you say in your original post? With the battery fully charged, and the engine running above idle speed, you want to see about 6.8 volts across the battery. Your description in your post sounds like the system is working correctly, except where you say the voltage drops and the system does not charge the battery.

As a precaution, check all your connections to the battery, generator and regulator looking for clean, bright metal surfaces and tight connectors. You can always check the battery to see if it is fully charged by use of a battery hydrometer, you should get a reading of 1.275 or higher in each cell.

Joe