29 Tudor charging system question

[ryanheacox]

Diode cutouts can be good, that’s what I use. Seems like if it’s not bad out of the box they will be trouble free. Berts has one listed on their site that they say is quality and I believe A&L still makes one, may be the same one. I don’t think that ammeter is original. All originals were satin black on the inside.

If you don’t want to take the dash apart, you can just leave that meter in there. It’s not hurting anything, just a place holder. It is nice to have working gauges though.

 

[fred93]

Update--I removed the diode cutout and it is N/G I can buy another diode for $6.00 But I decided to look on my shelf to see if I saved the old cutout. I actually found three of them. One looks like an original but the contact points were pretty much burned up. Another one looked okay so I cleaned the points and used the cover from the one that looked original.

I installed it on the car and it seems to be working okay. One thing that I noticed was that the voltage output from the generator climbed up to 10.0 volts. That seems a little high. Any thoughts on that??

I know that there is a third brush in the generator that can adjust the output--but does it also adjust the voltage???

 

[J Franklin]

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Just not looking forward to taking the dash panel apart.

4 screws, 2 thumbnuts, and maybe a clamp, and the thing comes out. It can't be too daunting.?

 

[J Franklin]

Update-

I installed it on the car and it seems to be working okay. One thing that I noticed was that the voltage output from the generator climbed up to 10.0 volts. That seems a little high. Any thoughts on that??

I know that there is a third brush in the generator that can adjust the output--but does it also adjust the voltage???

What Amperage does it show? Check your grounds because the generator is not regulated. 10Volts will fry your lightbulbs, and is an indicator.

 

[fred93]

What Amperage does it show? Check your grounds because the generator is not regulated. 10Volts will fry your lightbulbs, and is an indicator.

Since the ammeter is not working I'll have to use my Fluke meter. Tomorrow maybe. When I first started the engine the voltage went up slowly from 8 volts to ten volts.

I did check the grounds and they seemed ok but I'll check them again.

 

[fred93]

4 screws, 2 thumbnuts, and maybe a clamp, and the thing comes out. It can't be too daunting.?

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When I originally installed the dash panel I thought I was putting 10 pounds of potatoes into a 5 pound bag. Not fun.

 

[J Franklin]

Wouldn't creeping voltage indicate a heating joint with increasing resistance.

 

[fred93]

Diode cutouts can be good, that’s what I use. Seems like if it’s not bad out of the box they will be trouble free. Berts has one listed on their site that they say is quality and I believe A&L still makes one, may be the same one. I don’t think that ammeter is original. All originals were satin black on the inside.

If you don’t want to take the dash apart, you can just leave that meter in there. It’s not hurting anything, just a place holder. It is nice to have working gauges though.

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I thought that the diode type cutouts would be the best way to go. I can't remember where I bought this one (it must have been six years ago) but it has only been used approximately two plus hours and now it is N/G!

Should I buy a new diode and replace the one that is bad??? Amazon sells one for $6 plus shipping.

If I buy a new unit it will cost me $60 or more!

I have trust issues with the old style cutouts.

 

[Jim/GA]

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I thought that the diode type cutouts would be the best way to go. I can't remember where I bought this one (it must have been six years ago) but it has only been used approximately two plus hours and now it is N/G!

Should I buy a new diode and replace the one that is bad??? Amazon sells one for $6 plus shipping.

If I buy a new unit it will cost me $60 or more!

I have trust issues with the old style cutouts.

Yes, if you can solder it in, buy a new diode.

 

[rotorwrench]

For those that haven't seen an original ammeter, I'm posting this link from Vince's site.
http://www.fordgarage.com/pages/ammetertool.htm

The originals were not fancy by any means but the needle movement was consistent and much more sensitive than any repro I've yet seen.

A person working on the 3-brush type power generating systems needs to think in amps and not worry so much about volts. The voltage is controlled by the battery so it's very important that the battery be in good condition and well connected. When you adjust the 3rd brush, you are adjusting output amperage. Voltage is basically along for the ride in terms of voltage values.

A generator has to be able to generate a current/voltage by the amount of residual magnetism in the field pole shoes to even come on line since that is what closes the cut out switch. Once it's on line then it has the battery to control the voltage output and the 3rd brush to control the amperage/current output. The only bad thing about the original system is that it has to put out a constant current to keep up with the load. There is no rest for the weary and battery can be overcharged by the system if the load is low with high output current. It's not all that good for the generator either. If a person runs the car during the day then the 3rd brush can be set low but if you run at night a lot then it has to be adjusted back up again. This practice is not always followed that well. If you run with the lights a lot and don't want to adjust the output all the time then you have to run with the lights on all the time.

I've seen repro plastic terminal boxes melted due to loose wiring in there. Poor connections equal high resistance in the system and high resistance equals high temperature of the problem area. The wiring and ground pathways have to be maintained in good clean condition with tight connections to minimize problems.

 

[fred93]

For those that haven't seen an original ammeter, I'm posting this link from Vince's site.
http://www.fordgarage.com/pages/ammetertool.htm

The originals were not fancy by any means but the needle movement was consistent and much more sensitive than any repro I've yet seen.

A person working on the 3-brush type power generating systems needs to think in amps and not worry so much about volts. The voltage is controlled by the battery so it's very important that the battery be in good condition and well connected. When you adjust the 3rd brush, you are adjusting output amperage. Voltage is basically along for the ride in terms of voltage values.

A generator has to be able to generate a current/voltage by the amount of residual magnetism in the field pole shoes to even come on line since that is what closes the cut out switch. Once it's on line then it has the battery to control the voltage output and the 3rd brush to control the amperage/current output. The only bad thing about the original system is that it has to put out a constant current to keep up with the load. There is no rest for the weary and battery can be overcharged by the system if the load is low with high output current. It's not all that good for the generator either. If a person runs the car during the day then the 3rd brush can be set low but if you run at night a lot then it has to be adjusted back up again. This practice is not always followed that well. If you run with the lights a lot and don't want to adjust the output all the time then you have to run with the lights on all the time.

I've seen repro plastic terminal boxes melted due to loose wiring in there. Poor connections equal high resistance in the system and high resistance equals high temperature of the problem area. The wiring and ground pathways have to be maintained in good clean condition with tight connections to minimize problems.

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Thanks for the reply and the link--good info-

More questions--sorry!

I checked the generator max output and it is 12.30 amps--per your post this should be okay for a car that is driven mostly in the daytime.

Per my test yesterday-when I first started the engine the voltage started at around 7 volts and the longer the engine ran the higher the voltage went up, until it got up to 10 volts--then I shut it down. Why would the voltage go up to 10 volts.

I also noticed something else today. While running the engine at a high idle and I turned on the headlights the amp output of the generator dropped to 6+ amps (which I feel is about normal) BUT as soon as I turned on the headlights the engine rpm dropped noticeably--is that normal???

I also did a test light check of the cutout this morning--photos attached. That test did not seem to agree with your post above????

 

[redmodelt]

For day driving the amps would be 0-1+ side with head lights on and around 4-6 with them off with the RPM at approx equal to about 20 MPH. This could very depending on what type bulbs you are using, your trip length on average, if you use the headlight during the day etc. More output equals more heat/wear on the generator and higher drag on the engine. I would lower the output.

Reading stories from back in the day, you would have your generator out put adjusted to the type of driving you did. If you were going on a long trip you would have it turned down so you didn't boil the battery dry or drive all the time with the headlight on. I drive with my head lights on when we go on tours to both keep the charge rate down and for safety with my Model T, which has original style cutout and pretty much the same generating system as the A.

 

[Jim/GA]

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Thanks for the reply and the link--good info-

More questions--sorry!

I checked the generator max output and it is 12.30 amps--per your post this should be okay for a car that is driven mostly in the daytime.

<snip>

I also noticed something else today. While running the engine at a high idle and I turned on the headlights the amp output of the generator dropped to 6+ amps (which I feel is about normal) BUT as soon as I turned on the headlights the engine rpm dropped noticeably--is that normal???

<snip>

A 12 amp charge rate is too much for a car that is driven mostly in the daytime. It will boil the water out of your battery fairly quickly UNLESS you drive with your lights ON during the day. Even then, 12 might be kind of high in summer.

The Ford Service Bulletins said use a 10 amp charge rate for normal driving, which would include some night driving. Commercial and delivery vehicles (that are driven primarily in the day) only need a rate of 3-6 amps, they say (page 391 of the Service Bulletins). See also page 209 where they say 10 amps in summer, 14 in winter, and 8 if you drive mainly during the day.

Hope this helps.

 

[fred93]

A 12 amp charge rate is too much for a car that is driven mostly in the daytime. It will boil the water out of your battery fairly quickly UNLESS you drive with your lights ON during the day. Even then, 12 might be kind of high in summer.

The Ford Service Bulletins said use a 10 amp charge rate for normal driving, which would include some night driving. Commercial and delivery vehicles (that are driven primarily in the day) only need a rate of 3-6 amps, they say (page 391 of the Service Bulletins). See also page 209 where they say 10 amps in summer, 14 in winter, and 8 if you drive mainly during the day.

Hope this helps.

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Thanks for the reply--I will most likely lower that amperage.

But the voltage of 10 volts worries me. Anyone have any thoughts on that issue. Could the high voltage be the cause for the diode cutout and the ammeter going bad at the same time???

The owner will probably not drive this car too much. He has a trailer that I am sure he will use for any long trips to shows and such.

 

[Jim/GA]

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Thanks for the reply--I will most likely lower that amperage.

But the voltage of 10 volts worries me. Anyone have any thoughts on that issue. Could the high voltage be the cause for the diode cutout and the ammeter going bad at the same time???

The owner will probably not drive this car too much. He has a trailer that I am sure he will use for any long trips to shows and such.

As mentioned by someone else in an earlier reply, the VOLTAGE is set by the battery. The generator will push out the amps you have it set for (and as we agreed, 12 is too high) at whatever voltage it takes to push out those amps.

So set the charge rate down to 8 and see what your volts do.

Also (and you may think I'm nuts) turn the headlights on for about 10 minutes with the engine off to take some of the charge out of the battery. Then start the engine and read the volts when charging 8 amps with the headlights off and on. An overcharged battery will act very strangely, so taking some of that charge out can help it behave.

You might even have a defective battery. They will also push the volts up. I've seen it before.

 

[Patrick L.]

I wouldn't worry much about the 10v charge either. These generators are capable of 30v [usually when there is a bad ground somewhere.]

I keep the charge rate at 2-3 amps. I don't drive at night much.

I prefer the original cut-outs, they are pretty bullet-proof.

 

[Y-Blockhead]

I don't know if this is an original or not. It works--I replaced it because it looks bad. See photos.
Any thoughts from anyone if it is original???

That ammeter looks original from what I can tell. Or it might be a very old reproduction. Either way it looks pretty good and it will work better than the one you currently have.

I was told many moons ago that the quick and dirty way to determine if an ammeter is an original is to check to see if it is painted black inside 'to hide the workins'. (see picture). Since his is not, I would have to say it is a repro. They can be checked without removal or disassembly. Quick check while perusing the Swap Meet or buying a used one.

Photo courtesy 'Model A Ford Garage'.

 

[rotorwrench]

That big C shaped ring is another give away for an original type. I've not seen it in the reproductions.

The other posts are correct about the voltage change. Bad batteries and wiring in poor condition or loose connection can cause higher voltage depending on how high the 3rd brush is set. Ohm's law pretty well accounts for higher voltage if current output is high. The resistance, amperage, and voltage all affect each other according to Ohm's Law.

 

[redmodelt]

RE" Also (and you may think I'm nuts) turn the headlights on for about 10 minutes with the engine off to take some of the charge out of the battery. Then start the engine and read the volts when charging 8 amps with the headlights off and on. An overcharged battery will act very strangely, so taking some of that charge out can help it behave."
Not nuts at all! I have read instructions for at least one early car that suggested leaving the lights on over night for just that reason.

 

[fred93]

That big C shaped ring is another give away for an original type. I've not seen it in the reproductions.

The other posts are correct about the voltage change. Bad batteries and wiring in poor condition or loose connection can cause higher voltage depending on how high the 3rd brush is set. Ohm's law pretty well accounts for higher voltage if current output is high. The resistance, amperage, and voltage all affect each other according to Ohm's Law.

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Thanks for your reply-

The battery is six months old and I keep it charged up so that if I need to move the car I will be ready.

I have replaced ALL of the wiring in this car. After I did the wiring I checked everything to make sure it works. I am very well educated in automotive electrical repair. I always make sure that all connections are clean and tight. And well grounded! I have even added additional ground wires where needed. There is a non-original (I think it is not original) ground strap that is attached to the transmission and then to the frame. The ground strap that connects to the battery is new and the frame was ground down to bare metal where that strap attaches to the frame. I have checked all my grounds with a Fluke 88 meter and they all checked out okay.

Sorry if I seem to be ranting but I am very frustrated at this point since I am very close to having this project finished and giving it back into the hands of the owner instead of sitting in my shop (which it has been for the last ten years due to multiple health issues!!!)

If I need to purchase a new generator so be it--I need it finished!!!!