This has always been a weak point for me in all the years i have been working on cars, and continues to this very day. My question is this..when running on magneto like i do every time i run it, does the generator still charge the battery when the switch is on magneto? I have a new generator and a FP voltage regulator but the meter still only reads about a few pegs above zero when running. I adjusted the third brush to what was suggested but to no avail. Am i doing something wrong here?
It will/should charge in mag mode.
If the third brush is set up per VR's instructions it sounds like you are ok.
If the VR's set voltage is say 7.2V, a few amps may be all the battery requires to make the set point.
A discharged battery will take quite a few amps, a charged battery will take just a few to maintain that voltage. if you are hungry you eat a lot, if not, not so much.
Thanks Mike, that makes sense.
The 6v generator, starter and battery are entirely separate from the magneto.
You normally set the third brush with the stock Ford cut-out fitted - it should provide about 10A when revved up; not more than 12A. But you can't do this with the FP regulator. For this, the easiest test is to switch on the headlights. Then, when the engine speed is raised, the ammeter should be just above zero. It will be negative with the engine at idle.
With the lights off, the ammeter reading will depend on the battery charge state - higher current after using the starter motor a lot, for example.
Mike is right. Here is a photo about how your switch should be connected.
Yellow-black wire comes from the generator to one of the two battery spots on the switch. The small yellow-black wire go from the second battery spot to a terminal on the amp-meter. The yellow wire go directly to the battery.
The red wire is the magneto wire, the blue-yellow wire go to your coil box.
Black-red, black- blue and black-yellow are light wires.
Hope this will help.
It is important to remember the FunProjects Voltage regulator modulates the current output of the generator to the extent the battery need charging. As in the case where the engine has been started using the starting motor you can look at the ammeter and see the charging current. As the battery is replenished the the VR will instruct the generator to stop charging and the ammeter will return to zero..
When I drive my Model T just to make sure everything is working correctly I always peek at the ammeter immediately after starting the engine with the starting motor and expect to see an ammeter reading.
If you are driving and want to check the generator is working simply turn on the headlamps for 10 seconds and shut them off. You will see an ammeter reading till the battery is replenished when the ammeter needle will slowly move back to zero.
I always tell people who get the VR they need break themselves of looking at the ammeter and always expect to see charging current present.
Ron the Coilman
It was me the dummy.
I need to change the yellow wire and the yellow-black wire in the photo.
The yellow wire go to battery spot on the switch, the yellow-black wire go on the amp-meter.
Sorry for the mistake
I work on Model T charging circuits a lot, an occupational hazard of rebuilding generators, and those three connections (Yellow wire to starter switch hot side, Yellow with Black tracer jumper from ammeter to switch and the Yellow with-Black wire from ammeter to terminal block and ultimately the generator cutout) are involved in most of the troubles.
You would be surprised at the number of combinations of trouble incorrect connections of these three wires can exhibit.
Attached is a copy of a CORRECT Model T wiring diagram and it is the only one I will use when helping folks. That annoys some people who think there wiring diagram is correct, many times they are not.
Ron the Coilman
I don't see any error in your picture. The yellow/black wires should be wired just as you pictured it. There are NO solid yellow wires that are connected at the switch. There are only 2 solid yellow heavy wires in the car. One from the battery side of the starter foot switch which then goes to terminal number 3 (3rd from the left as you view the terminal block on the firewall). A second solid yellow heavy wire then continues from that same terminal 3 on the barrier strip and proceeds to one side of the ammeter. The other side of the ammeter than begins the series of 3 yellow/black wires that go from the ammeter to the BAT terminal on the switch then continues to terminal number 1 of the barrier strip then continues to the cutout (or VR) screw terminal output connection.
Your posted picture seems to show the wiring portion of the switch and ammeter correctly done.
For those saving things, here's Ron's diagram with the paper surface removed.
I think what is confusing people is that in the above diagram the yellow/black wire is shown to be connected to the terminal farthest away from the switch while the Andre's picture shows the yellow wire connected to the terminal furthest away from the switch. Ford in fact allowed the ammeters to be manufactured either way as long as the terminals were marked with the correct + and - polarity on the back. The solid yellow wire would go to the + terminal if it was marked on the ammeter. Thus the picture is in fact correct unless the ammeter is reading backwards in which case only the 2 wires at the ammeter need to be interchanged. There should not be 3 wires terminating at the ammeter. The meter in the picture is not a typical meter for that switch/ammeter panel but is a 26/27 type meter being mounted using the adapter plate that Ford made up later so that he could sell the smaller meter as a replacement for the earlier larger meter.
Well I goofed too. I meant to say that the + terminal of the ammeter should go to the Yellow/Black wire regardless of whether that is on the left or right side of the ammeter. I am up too late and need to go to bed since I am getting fuzzy in my postings.