Ammeter Shows No Charge

[rotorwrench]

What are the readings on the multi meter set on voltage and taken at the battery when the car is running? What are the the readings at the output end of the cut out in the same conditions? Is the voltage higher than the normal fully charged battery reading at rest? Normal average reading for a 6-volt in good condition is 6.2-volts. A battery that is charging should be a fair bit higher than that. Likely around 7.1 volts or so give or take a bit. That can depend on the 3rd brush adjustment.

When the generator was run with both higher voltage and reverse polarity, the generator may still have reverse polarity problems. If there was a short that caused a peak current draw through the ammeter, it can damage the ammeter. Does your car have an original ammeter or a reproduction?

I would start by checking the cut out relay or power diode as applicable. It is designed to pass current if the generator is charging. The current should be around 4 or 5 amps minimum. I would definitely re-polarize the field pole shoes as well.

An original type cut out relay is designed to bring the generator on line as soon as the generator output exceeds the battery normal voltage range. Putting an 8-volt battery in there changes the generator output voltage due to the battery being the only thing that regulates system voltage. It's not supposed to put out 9-volts but it will and it may have overheated the armature. I don't recommend using anything but 6-volts around a 3-brush generator with no voltage regulator other than the battery.

Amperage is always read through the meter so any ammeter used to check the system has to be placed in the line. There is no contact to ground as there is when checking voltage. The original ammeters Ford used are far superior to the new reproductions. The originals use a horse shoe magnet mounted inside. The reproductions use a rare earth magnet and I'm not fond of those set ups.