Generator Voltage
 

I have a "new to me" (~running) 30 Tudor that I have been trying to make reliable.
I have come across several problems that thanks to you Ford Barn Gurus have been easy to fix.

My latest problem happened when I want to install the Fun Project regulator.
When I was adjusting the third brush for the proper amperage I also checked the voltage. When the throttle was raised to show a charge I checked the voltage it was ~9 volts the lights were very bright and when I used the horn it screamed.

My question is what determines the generator VOLTAGE output, and how it can change?

Re: Generator Voltage
 

whats a fun project regulator? :)

Re: Generator Voltage
 

A regulator that replaces the cutout.

Re: Generator Voltage
 

Okay did not know that.

Re: Generator Voltage
 

The regulator you just bought.

Re: Generator Voltage
 

The Model A and several other early cars had unregulated generators. Moving the third brush will set the amps to a constant amp output, but if the battery is out of the circuit the voltage can go as high as 40 volts. That's why electronic voltage regulators are such a good thing. With an EVR the voltage is regulated to about 7.2 to 7.5 volts, so even if the charging circuit has a poor connection or blown fuse, the generator will still maintain a safe output and not blow all the lights.

Re: Generator Voltage
 

Thanks Tom,
Interesting, so in my case the generator is not recognizing the full voltage from the battery so it is producing a higher voltage? Would that mean, for example, if there were a 12 volt battery the generator would charge at 13 volts?

I have a nearly new 6 volt battery (3 Cells). The starter sounds like it is has plenty of current. I'm don't know why the generator is not seeing 6.6 volts.



So putting a voltage regulator in a charging system that is producing a higher than normal voltage is OK as long as the amperage is below 10A at full charge?

Re: Generator Voltage
 

Is the regulator installed now?

With the car not running what is the voltage at the battery?
With the car not running what is the voltage at the generator?
With the car running what is the voltage at the battery?
With the car running what is the voltage at the generator?

Re: Generator Voltage
 

FWIW:

If you do "not" have the Fun Projects Voltage Regulator Written Instructions, or if you "do", & have a few questions, please call Electrical Engineer Mr. John Regan, President of Fun Projects, at (630) 584-1471 who designed this regulator -- absolutely no doubt he can help.

I bought mine many years ago & I called him to ask a simple question prior to installing mine much later & this gentleman went into exacting details to explain prior checks to perform using my Wal-Mart GE analog multi-meter.

Just be prepared to follow explicit orders like they are coming from the notorious U. S. Army General George Patton -- he is an experienced absolutely no B.S. gentleman -- most fun I ever had in my entire life was listening to his "orders" of what to do next.

He has a wonderful product that can make batteries last a lot longer.

He said even if you ruined your regulator, do "not" throw it away -- he can repair it.

Just sincerely hope this helps -- may God bless Mr. John Regan & his wonderful family.

Re: Generator Voltage
 

Hster, If your third brush is set for full output, or if your battery is too small or worn out, you can get the 9 volts you were showing. Have you tried setting the third brush to a lower output? I had a worn out battery in my 29 Tudor when I bought the car, and the powerhouse was charging it at 16 volts at fast idle. That's why I made an electronic voltage regulator for it.

Yes, if you change to a 12 volt battery, then the stock generator would charge it at the set amps, unless you installed a voltage regulator, then the voltage would be regulated and the amps output would change depending on demand.

Re: Generator Voltage
 

If I am not mistaken the "Fun Projects Regulator" comes in more than one configuration. If I remember right they offer 6 and 12 V versions in + & - ground configurations. Is there a chance that you received the wrong one for your application?

Re: Generator Voltage
 

And 8 volts if I am not mistaken

Re: Generator Voltage
 

Not mistaken.

Fun Projects

Re: Generator Voltage
 

Is the regulator installed now? Not yet

With the car not running what is the voltage at the battery? 6.6A
With the car not running what is the voltage at the generator? 0
With the car running what is the voltage at the battery? Idle 6.6A Under throttle 9A
With the car running what is the voltage at the generator? Idle 0 Under throttle 9A

Re: Generator Voltage
 

Thanks H.L.

I'll give him a call monday . I must say every person I have talked to about Model A stuff has been interesting and more than willing to share their knowledge and information, very refreshing in this day.

Re: Generator Voltage
 

Tom,
First let me say I think you are one of the Ford Barn Owls (as in wise not flighty).

Yes, I have moved the third brush to change the generator output it is now set @ 10A.
However I did not check the voltage at different brush settings.

The battery is six moths old. I don't know what the amp hour rating is but it fills the battery box, and turns the starter much faster than my Pickups starter.

After looking at the voltages It sure looks as though the generator is the culprit. Is it possible the field windings could be shorting internally?

I have a FPR on my Pickup and am very happy with it. I installed it without issue.
There has been several issues with the Tudor that I have discovered that indicate whoever did the work had little skill and understanding of the workings of a Model A. I'm not am by no means an accomplished mechanic, but I have been careful to do work that is in keeping
with the Model A's practice. That being said the Tudor has turn internal signals, that is to say, in the cowl lights (two bulbs) and in the tail lights. I am dubious as to wether the wiring is correct after looking at the previous work. For example, the cowl lights are on with the high and low beams on and the lights pull over 15A.

Do you rebuild generators? I have a "spare" that needs work and by the look of it maybe the one thats in the Tudor.

Re: Generator Voltage
 

You should just set the generator output according to the instructions with your regulator, then install the regulator and see how things go.

If the fields were shorted or open, the output would drop.

Re: Generator Voltage
 

I will do that. I just thought everything should be woking properly before installing FPVR.

Re: Generator Voltage
 

The FPVR works Just as it should.

I just don't get how the voltage could have been so high. Oh well, I guess it doesn't matter now as long as it works.

I still have a problem with the lights drawing -10 amps at driving speed. If I turn off the lights I'll get an initial 12amp charge that reduces as the battery is charged, so the charging system is as it should be.

Sorry for the bother

Re: Generator Voltage
 

If you have sealed beam headlights, you may have to set the third brush to full output to produce the maximum amps. I have an electronic voltage regulator on my generator on a six volt positive ground system and had to move the third brush to max output to keep the battery from discharging on low beam. Hi beams use more amps than the generator produces, so I have about a five amp discharge when using the hi beams! I drive a lot at night and that slight discharge has never run the battery down to where it was noticeable. With the EVR I only show about a one amp charge with normal daytime driving even though the third brush is at full output! Was well worth the money spent on it!