29 Tudor charging system question
 

Finishing the 29 Tudor.

Today I started the engine and I noticed that the ammeter just stayed at zero. So I turned on the headlights so see if the ammeter moved--it didn't move at all.

The ammeter is new (probably only has a couple hours of running time). The ammeter has always shown a charge with the engine running but today it shows nothing-just sits at zero. I turned off the engine and turned on the headlights again--nothing-still zero. I gave it a gentle tap--nothing!

I started the engine again and took a voltage reading at the battery--6.65 volts. I took a reading at the generator output wire and it read 7.94 to 8.00 volts. I took another reading at the output post of the cutout--it read 6.65 volts.

I assume that the cutout is not working. It is also new (diode type) . (I had a fellow that worked at my auto repair shop and his quote was "New means NOT tested")

Can I bypass the cutout with a jumper wire-as a test to see if the cutout is bad? or do I need to just replace the cutout?

Re: 29 Tudor charging system question
 

If the ammeter needle does NOT move when you turn on the headlights, as I think I understand from you, the ammeter is not connected properly or the ammeter is defective.

Start there.

The diode cutout might also be bad, but you need to get the ammeter working first.

Trace the wires from the generator to the terminal box to the ammeter to the terminal box to the starter switch. Something in there is not right.

When you turn the headlight switch on, do the lights light up? If so, the headlight switch is getting power from somewhere. If not, that's why the ammeter needle is not moving.

If wired correctly, the ammeter might just be defective. Is it an original or a reproduction? The repro ammeters are notorious for being defective.

:cool:

Re: 29 Tudor charging system question
 

Had the exact same thing happen to me yesterday--I just hit the ammeter with the palm of my hand forcefully a couple of times and bingo--everything worked. This has happened to me a few times so know the routine for my setup.

Re: 29 Tudor charging system question
 

Everything worked fine until today. The ammeter always showed a charge with the engine running at high idle.

When the engine was not running the ammeter always showed a discharge when I turned on the headlights.

The ammeter is a new repro.

The cutout is a new diode type.

Both have been on the car for at least three years BUT they have only a few hours of run time on them.

Re: 29 Tudor charging system question
 

I suspect the ammeter is defective. Highest probability explanation. Start there.

.

Re: 29 Tudor charging system question
 

A diode cutout looses about 1/2 volt going through it,

Re: 29 Tudor charging system question
 

Maybe I was not clear on my details.

With the engine running and using a Fluke meter I get 8.00 volts going into the cutout and only 6.5 volts coming out of the cutout. (actually the 6.5 volts is just what the battery is providing)

That seems to me that the cutout is not letting current go through the cutout.

Can I bypass the cutout with a jumper wire to test the ammeter?

Re: 29 Tudor charging system question
 

Sure! As a temporary test; don't leave it connected. Have the RPM up high enough that you get the 8 volts, touch the wire on there.

Re: 29 Tudor charging system question
 

Interesting, but even if the generator and the cut-out were totally defective, you should still get a discharge reading on the ammeter when the lights are on whether the engine is running or not. That still points to an ammeter issue in my opinion.

Re: 29 Tudor charging system question
 

7b0

Re: 29 Tudor charging system question
 

The amp meter is not dependent on the voltage regulator/cut out to show a discharge. If it isn’t moving then you have a wire loose or it’s defective. The cut out working or not working changes the readout of the amp meter, but you will still have a readout regardless of whether the cut out is open or closed.

Re: 29 Tudor charging system question
 

I can't believe that so many of the parts that I have bought for this car have turned out to be junk.

I sent all the shocks out to Robert Paul years ago and the two front shocks started leaking after several years of just sitting in the garage. (I don't know what I am going to do about that problem yet)

I purchased two new hood shelves from Bratton's that did not fit (they refunded me on those). And I bought new ones from Bert's that do fit.

The floor mats that I bought from Bratton's did not fit--they refunded me on that--I finally got a good set from Snyder's.

I went through several pieces of new window glass from Bert's--they had bad scratches on the glass--Bert's worked with me on those and I finally got a good set.

I bought brand new authentic cooling hose clamps that are not worth a s**t. I found some really good ones at a plumbing store.

I bought a brand new fuel sediment bulb that leaks like a sieve--I removed the screen to elevate that problem and installed an aftermarket filter inside the glass bulb

Now I have a bad cutout AND a bad (presumably) ammeter! Both items were purchased several years ago but they only have a few hours of run time on them!

For test purposes I disconnected the wire coming from the generator to the cutout and placed a jumper wire from that wire to the wires that are attached to the output side of the cutout--please see photo for more clarity. With the engine running at high idle and the jumper wire in place, I then have 7.97 volts going into the battery. However, the ammeter still did not move off of zero.

Correct me if I am wrong---since the headlights and dash light is working then the ammeter is not fried??? but it is just not working???

I read somewhere that the ammeter is somewhat like a fuse--if too much current is going through it, it will just burn out???

Re: 29 Tudor charging system question
 

Correct, not fried and not working. Almost all of the current going through the ammeter is going through a shunt. A small amount goes through a fine winding between two magnets which will swing the needle either way. That winding could have fried, broken or who knows. The new ammeters really are junk. It's probably just as accurate with the needle at 0 as it was when it was moving.


As far as the bad cutout... yep I've got one too except if failed closed, acted just like your jumper. Was a new in box diode cutout... oh well.

Re: 29 Tudor charging system question
 

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So where do I go to buy a GOOD ammeter and a GOOD cutout?

If everything is junk are we all just screwed??

Re: 29 Tudor charging system question
 

I would call Bert's and see if Steve has good used parts. I'm sure he has good cutouts both new and used. I think ammeters are a hot commodity though. I think most of the vendors pulled their stock... they were just that bad. Could also post a wanted ad here.

Re: 29 Tudor charging system question
 

You have to get an original ammeter - the repros have been junk for many years. Not too much goes wrong with originals - there is basically just a magnet inside with a pointer on it that is very fragile.

Re: 29 Tudor charging system question
 

A person can easily run the car without one. A jumper across the two posts on the junction box will bypass the ammeter and get you on your way.

Re: 29 Tudor charging system question
 

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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???

I may just make one out of the two!

Just not looking forward to taking the dash panel apart.

Re: 29 Tudor charging system question
 

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Are the diode cutouts junk?

Back in the 60's when I first started working on A's the cutout would stick closed and you had a dead battery. I thought that the diode would alleviate that problem!

I may have an older cutout, but I doubt it is original--but i know it is not a diode type.

Re: 29 Tudor charging system question
 

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.

Re: 29 Tudor charging system question
 

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.

Re: 29 Tudor charging system question
 

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???

Re: 29 Tudor charging system question
 

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

Re: 29 Tudor charging system question
 

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

Re: 29 Tudor charging system question
 

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.

Re: 29 Tudor charging system question
 

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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.

Re: 29 Tudor charging system question
 

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

Re: 29 Tudor charging system question
 

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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.

Re: 29 Tudor charging system question
 

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

:cool:

Re: 29 Tudor charging system question
 

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.

Re: 29 Tudor charging system question
 

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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????

Re: 29 Tudor charging system question
 

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.

Re: 29 Tudor charging system question
 

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.

Re: 29 Tudor charging system question
 

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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.

Re: 29 Tudor charging system question
 

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.

:cool:

Re: 29 Tudor charging system question
 

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.

Re: 29 Tudor charging system question
 

Re: 29 Tudor charging system question
 

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.

Re: 29 Tudor charging system question
 

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.

Re: 29 Tudor charging system question
 

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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!!!!