Re: The Duchess Project: 1940 Super 8 Convertible Sedan

Posted by TxGoat On 2023/6/1 21:40:53

The Optima batteries have somewhat different characteristics than the flooded cell, lead-acid batteries that the old style voltage regulators are designed for. I'm not sure whether that's the cause of your problems or not.

It appears that your generator works, and that something is destroying your voltage regulators. It may be that the Optima batteries are not compatible with the early style regulators. For what it's worth, I have a Model T Ford that has an Optima red top 6 volt battery and the stock generator-cutout arrangement. It's worked fine for the two years I've had the car and the many miles I've driven it. Of course, the Model T has no voltage regulator. It has a simple cut out relay, and no automatic voltage or current regulation whatsoever.

You might try running your car with a single Optima battery, making sure that polarity is correct and that there are no wiring problems.

I'm not sure of the correct "field flashing" generator polarizing procedure for your car. Starting the car with improper polarity could trash the regulator. Regulators are fairly sensitive devices.

I believe that a 6 volt externally regulated generator would show very low resistance continuity to ground at the ground terminal, and also the field terminal and the armature terminal on the generator.

It's important that the voltage regulator base has a good electrical ground to the generator housing. Some regulators have rubber vibration isolators built into their mounting arrangement, and they must have some type of electrical ground. In some cases, adding a ground wire, if one does not already exist, from the metal regulator base to the generator ground terminal will give good results.

Voltage regulators can be destroyed very quickly if wiring problems, serious battery issues, or reverse polarity exist. The generator itself is a good deal more rugged, and old fashioned lead-acid batteries can stand up to some abuse.