VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 '32 ammeter normal resistance ?

Does anyone know what the acceptable voltage drop is between the generator and the battery ? My multimeter indicates 7.16v at the generator and 6.58v at the battery at a slightly high idle. In other words, an approximate .58v loss somewhere between the genny as it flows through the ammeter and direct to the battery.

I by-passed the ammeter with a jumper wire between the 2 terminals on the back of the ammeter. The loss then was a little less, .46v . Not .58v as unjumped.

Before I go chasing down bad wires, connections, could this be a normal resistance in the ammeter ? It's original as far as I know. Only 91 years old.

The red indicator needle doesn't seem to move much, left or right, since I installed the solid state regulator a few years ago.

Thank guys.

Can you describe the rest of the electrical system? Are you still running the original 3 brush generator?

Or did you upgrade to a 2 brush generator when you installed the solid state regulator?

I also have the solid state "Petersen" regulator and the needle barely moves but I have never had a battery charge problem. I did learn that the battery disconnect switch I was using was causing voltage drop so I swapped it out . I am not an electrical expert but I don't think a 1/2 volt drop is anything to be concerned with.

It's basically a stock 6v negative ground system except for the Peterson solid state regulator. The 3rd brush was removed to allow room for the new regulator inside the generator band. I recall a diode cutout was part of the install. Maybe there's a voltage drop across the diode itself and it's designed into the system.

This all was installed a few years back, with no issues, but I never looked into if the set up was optimized, until now.

I have 2 x 6v Optima batteries in parallel that show 6.36v after a full charge from my Schumacher charger.

I have been running a Peterson regulated generator for about 20 years. It is in a 1931 generator that I switch into my 1928 Coupe or the '31 Phaeton or what ever I happen to be driving in that year range. It also still has the third brush set to about 8 amps to protect the armature from overheating. Never had a problem even though it still has the original points type cut-out. Peterson insisted on a diode but I resisted.

I also installed a heavy duty battery disconnect switch to make surest didn't cause a problem.

I posted this thread after a hard start yesterday purt'n near drained down my batteries. After she started I went probing around looking for a problem since I noticed the amp needle didn't' swing to the charge side.

Chipper, how did you fit that gadget inside the genny housing with the 3rd brush, or is it mounted on the outside ?

Nice to hear you have more resistance than a diode.

The regulator fit inside. Was mounted on the band in a location between the brushes.