29 Tudor charging system question

[Jim/GA]

Have you set the charge rate down to 8 amps and measured the volts at the battery again?

It sounds like you really need a different ammeter. Call Bert's.

[fred93]

Originally Posted by Jim/GA

Have you set the charge rate down to 8 amps and measured the volts at the battery again?

It sounds like you really need a different ammeter. Call Bert's.

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Thanks for your reply

I just did another test on the generator output.

Please note that the ammeter in the car does not work at all at this point.

I am using my Fluke 88 meter to see what the amperage is coming from the generator. I used another multi meter to check the voltage at the same time.

At a fast idle-
With high beam headlights ON-
voltage--6.50
amperage--7.2
All readings were pretty steady.

At a fast idle--
With headlights OFF-
voltage--Climbing to 8.4 volts
amperage--Also climbing to 11.0 amp (I had the engine for at least 20 minutes and the voltage and amperage did not go any higher)

I have moved the third brush in the generator as far as I could and it would only lower the amperage to about 10 amps at a fast idle.


Someone suggested that I place a jumper wire between the two connection studs in the terminal box on the firewall. I did that it it made no change in voltage or amperage.

[fred93]

Originally Posted by Jim/GA

Have you set the charge rate down to 8 amps and measured the volts at the battery again?

It sounds like you really need a different ammeter. Call Bert's.

**************************************************

I finished rebuilding the generator. I also installed the old ammeter that was in the car when I started the restoration (I swapped the bezels so the old ammeter looks new--it works okay)

The generator puts out 6 amps at fast idle with 7.5 volts steady!

Two questions though--

#1--I hear a whining noise coming from the generator at high idle. If I take a plastic stick and touch the 3rd brush the whine goes away. I am thinking that maybe that whine will go away when the brush seats in???

#2--When I turn on the headlights the dash ammeter reads negative 6 amps. I assume if the generator is only putting out 6 amps that when the headlights are turned on a discharge reading would be normal. I guess if the car is going to be driven a lot at night I would need to adjust the 3rd brush. Seems like a PITA to me!

[Jim/GA]

Originally Posted by fred93

**************************************************

I finished rebuilding the generator. I also installed the old ammeter that was in the car when I started the restoration (I swapped the bezels so the old ammeter looks new--it works okay)

The generator puts out 6 amps at fast idle with 7.5 volts steady!

Two questions though--

#1--I hear a whining noise coming from the generator at high idle. If I take a plastic stick and touch the 3rd brush the whine goes away. I am thinking that maybe that whine will go away when the brush seats in???

#2--When I turn on the headlights the dash ammeter reads negative 6 amps. I assume if the generator is only putting out 6 amps that when the headlights are turned on a discharge reading would be normal. I guess if the car is going to be driven a lot at night I would need to adjust the 3rd brush. Seems like a PITA to me!

#1 - correct. If the noise does not go away in a few days, look at the way you have the brushes installed. You may have one at an angle that is hitting the rotating copper bits on the shaft, making the buzz.

#2 - correct. The generator puts out a constant current, regardless of how much you actually need. A crude, but effective, design. Ford had car owners bring their cars in for service often and adjusting the generator charge rate for the season and type of use the car saw was part of the service.

Your 6 amp charge rate is adequate for a car that has a battery minder connected up to it while it is parked in a garage between uses. Then you are always going out with a fully charged battery. You can run at night for a few hours without killing the battery if you need to.

This PITA of adjusting the 3rd brush is why so many people install a hidden voltage regulator on the original generators. Then you get the current you need when you need it but less at other times, after the battery is charged.

As many of you know, I am not a big proponent of "modern upgrades" on the Model A because they often create more problems than they cure. To me, the voltage regulator is one exception. They really do help keep your battery charged without boiling the water out of it. They get you more current for lights when you need it. Worth installing.

[fred93]

Originally Posted by Jim/GA

#1 - correct. If the noise does not go away in a few days, look at the way you have the brushes installed. You may have one at an angle that is hitting the rotating copper bits on the shaft, making the buzz.

#2 - correct. The generator puts out a constant current, regardless of how much you actually need. A crude, but effective, design. Ford had car owners bring their cars in for service often and adjusting the generator charge rate for the season and type of use the car saw was part of the service.

Your 6 amp charge rate is adequate for a car that has a battery minder connected up to it while it is parked in a garage between uses. Then you are always going out with a fully charged battery. You can run at night for a few hours without killing the battery if you need to.

This PITA of adjusting the 3rd brush is why so many people install a hidden voltage regulator on the original generators. Then you get the current you need when you need it but less at other times, after the battery is charged.

As many of you know, I am not a big proponent of "modern upgrades" on the Model A because they often create more problems than they cure. To me, the voltage regulator is one exception. They really do help keep your battery charged without boiling the water out of it. They get you more current for lights when you need it. Worth installing.

************************************************** *

Thanks for the reply

Where would I get a voltage regulator??

Who sells the best unit??

[Patrick L.]

Sponsored Links (Register now to hide all advertisements)

I like the internal EVR build by Tom Wesenberg along with a good original cutout.

Some folks like the external FunProjects regulator.

[Purdy Swoft]

I use the Fun Projects voltage regulator, it takes the place of the cut out and NO modifications to the generator are necessary. I adjust my generator for a 10 amp maximum charge rate for better lights. The Fun Projects voltage regulator prevents the battery from overcharging. John Regan , the maker of the voltage regulator said that a ten amp maximum charge rate would work just fine and it does !!!

[fred93]

Originally Posted by Purdy Swoft

I use the Fun Projects voltage regulator, it takes the place of the cut out and NO modifications to the generator are necessary. I adjust my generator for a 10 amp maximum charge rate for better lights. The Fun Projects voltage regulator prevents the battery from overcharging. John Regan , the maker of the voltage regulator said that a ten amp maximum charge rate would work just fine and it does !!!

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Does the Fun Projects voltage regulator control amperage AND voltage output?

I thought that I read somewhere that Fun Projects has changed ownership recently--is that true? And has that changed the product at all?

[rotorwrench]

The Fun Projects VR only controls the amperage output but in doing so, it also controls the voltage to a degree since both increase and decrease at the same time per Ohms Law. The actual voltage control on all 3-brush units is always the battery voltage no matter what type of controller you add.

John Regan's design turns the generator on and off at a rate that acts as a control very much like a 2-brush voltage regulator pole controls the voltage. The on and off cycle is like a buzz since it happens very rapidly depending on the electrical load at any given time.

Birdhaven Vintage Auto Supply purchased the rights to Fun Projects and Texas T Parts but it's hard to tell what they are up to unless you call them. Both the Texas T and Fun Projects web sites are still up but I don't know if they update them or not.

[Purdy Swoft]

As rotorwrench says , the battery controls the voltage . Fun Projects offers a twelve volt version for use on the model A generator . Install a twelve volt battery , either change the coil to a three OHM coil or use a resister at the coil connection , Install the Fun Projects voltage regulator and you will have converted your model A to a twelve volt system . I run mine positive ground as original and no wires needed to be changed . If converting to negative ground the battery cables need to be connected as negative ground , the wires at the coil and ammeter need to be reversed . It is really a simple conversion . If the original six volt wiring is in good condition , it will carry the 12 volts without problems . The wiring on 12 volt systems are generally smaller gauge than what is used on 6 volts . The larger gauge wire that is used on six volt systems will handle 12 volts without problems .

I feel that if Ford still made model A's they would be set up as 12 volts . Six volts is only a bare get bye . Twelve volts gives a more powerful system that batteries and coils are readily available for . The bulbs will need to be changed. Model A generators and starters have worked well for me on 12 volts without problems for many years . As a matter of fact , I have never had a problem with either of them on 12 volts . The system generaly operates on lower amps on 12 volts .