Go Back   The Ford Barn > General Discussion > Model A (1928-31)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 06-10-2020, 05:01 PM   #1
fred93
Senior Member
 
fred93's Avatar
 
Join Date: Nov 2010
Location: SPRUCE PINE NC
Posts: 435
Default 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?
__________________
Why is there never enough time to do it right, but always enough time to do it over!!!
fred93 is offline   Reply With Quote
Old 06-10-2020, 05:14 PM   #2
Jim/GA
Senior Member
 
Jim/GA's Avatar
 
Join Date: May 2010
Location: Young Harris, GA
Posts: 1,612
Default 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.

__________________
Jim Cannon
"Have a Model A day!"
  • Repair
  • Restore
  • Drive
  • Enjoy!
  • Join MAFCA
http://tinyurl.com/Join-MAFCA
Jim/GA is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 06-10-2020, 05:18 PM   #3
MVal
Member
 
Join Date: May 2010
Posts: 66
Smile 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.
MVal is offline   Reply With Quote
Old 06-10-2020, 05:29 PM   #4
fred93
Senior Member
 
fred93's Avatar
 
Join Date: Nov 2010
Location: SPRUCE PINE NC
Posts: 435
Default Re: 29 Tudor charging system question

Quote:
Originally Posted by Jim/GA View Post
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.


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.
__________________
Why is there never enough time to do it right, but always enough time to do it over!!!
fred93 is offline   Reply With Quote
Old 06-10-2020, 05:55 PM   #5
Jim/GA
Senior Member
 
Jim/GA's Avatar
 
Join Date: May 2010
Location: Young Harris, GA
Posts: 1,612
Default Re: 29 Tudor charging system question

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

.
__________________
Jim Cannon
"Have a Model A day!"
  • Repair
  • Restore
  • Drive
  • Enjoy!
  • Join MAFCA
http://tinyurl.com/Join-MAFCA
Jim/GA is offline   Reply With Quote
Old 06-10-2020, 06:03 PM   #6
Kurt in NJ
Senior Member
 
Kurt in NJ's Avatar
 
Join Date: May 2010
Location: on the Littlefield
Posts: 5,286
Default Re: 29 Tudor charging system question

Sponsored Links (Register now to hide all advertisements)
A diode cutout looses about 1/2 volt going through it,
Kurt in NJ is offline   Reply With Quote
Old 06-10-2020, 07:55 PM   #7
fred93
Senior Member
 
fred93's Avatar
 
Join Date: Nov 2010
Location: SPRUCE PINE NC
Posts: 435
Default Re: 29 Tudor charging system question

Quote:
Originally Posted by Kurt in NJ View Post
A diode cutout looses about 1/2 volt going through it,
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?
__________________
Why is there never enough time to do it right, but always enough time to do it over!!!
fred93 is offline   Reply With Quote
Old 06-10-2020, 08:37 PM   #8
Jim/GA
Senior Member
 
Jim/GA's Avatar
 
Join Date: May 2010
Location: Young Harris, GA
Posts: 1,612
Default Re: 29 Tudor charging system question

Quote:
Originally Posted by fred93 View Post
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?
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.
__________________
Jim Cannon
"Have a Model A day!"
  • Repair
  • Restore
  • Drive
  • Enjoy!
  • Join MAFCA
http://tinyurl.com/Join-MAFCA
Jim/GA is offline   Reply With Quote
Old 06-11-2020, 12:26 AM   #9
Bill G
Senior Member
 
Bill G's Avatar
 
Join Date: Jun 2017
Location: Walla Walla, WA
Posts: 768
Default 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.
__________________
-Bill G
Member of Walla Walla Sweet A's Model A Club
Bill G is offline   Reply With Quote
Old 06-11-2020, 08:47 AM   #10
Benson
Senior Member
 
Benson's Avatar
 
Join Date: May 2010
Location: Snork Key
Posts: 2,100
Default Re: 29 Tudor charging system question

7b0

Last edited by Benson; 06-11-2020 at 11:03 PM.
Benson is offline   Reply With Quote
Old 06-11-2020, 07:02 PM   #11
Chuck Sea/Tac
Senior Member
 
Chuck Sea/Tac's Avatar
 
Join Date: May 2010
Location: Between Seattle & Tacoma
Posts: 2,006
Default 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.
Chuck Sea/Tac is offline   Reply With Quote
Old 06-12-2020, 11:17 AM   #12
fred93
Senior Member
 
fred93's Avatar
 
Join Date: Nov 2010
Location: SPRUCE PINE NC
Posts: 435
Default Re: 29 Tudor charging system question

Quote:
Originally Posted by Chuck Sea/Tac View Post
The amp meter is not dependent on the voltage regulator/cut out to show a discharge. If it isnít moving then you have a wire loose or itís 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.
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???
Attached Images
File Type: jpg IMG_6562.jpg (59.4 KB, 31 views)
__________________
Why is there never enough time to do it right, but always enough time to do it over!!!
fred93 is offline   Reply With Quote
Old 06-12-2020, 01:03 PM   #13
ryanheacox
Senior Member
 
ryanheacox's Avatar
 
Join Date: Apr 2013
Location: Northwest CT
Posts: 1,047
Default Re: 29 Tudor charging system question

Quote:
Originally Posted by fred93 View Post
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???

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.
ryanheacox is offline   Reply With Quote
Old 06-12-2020, 01:46 PM   #14
fred93
Senior Member
 
fred93's Avatar
 
Join Date: Nov 2010
Location: SPRUCE PINE NC
Posts: 435
Default Re: 29 Tudor charging system question

Quote:
Originally Posted by ryanheacox View Post
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.
+++++++++++++++++++++++++++++++++++++++
So where do I go to buy a GOOD ammeter and a GOOD cutout?

If everything is junk are we all just screwed??
__________________
Why is there never enough time to do it right, but always enough time to do it over!!!
fred93 is offline   Reply With Quote
Old 06-12-2020, 02:17 PM   #15
ryanheacox
Senior Member
 
ryanheacox's Avatar
 
Join Date: Apr 2013
Location: Northwest CT
Posts: 1,047
Default 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.
ryanheacox is offline   Reply With Quote
Old 06-12-2020, 03:28 PM   #16
chrs1961815
Senior Member
 
chrs1961815's Avatar
 
Join Date: Jul 2018
Location: Spring Grove, Illinois
Posts: 855
Default 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.
__________________
"The more things change, the more they stay the same."
chrs1961815 is offline   Reply With Quote
Old 06-12-2020, 05:32 PM   #17
Bill G
Senior Member
 
Bill G's Avatar
 
Join Date: Jun 2017
Location: Walla Walla, WA
Posts: 768
Default 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.
__________________
-Bill G
Member of Walla Walla Sweet A's Model A Club
Bill G is offline   Reply With Quote
Old 06-12-2020, 06:21 PM   #18
fred93
Senior Member
 
fred93's Avatar
 
Join Date: Nov 2010
Location: SPRUCE PINE NC
Posts: 435
Unhappy Re: 29 Tudor charging system question

Quote:
Originally Posted by ryanheacox View Post
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.
+++++++++++++++++++++++++++++++++++++++++
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.
Attached Images
File Type: jpg IMG_6585.jpg (47.6 KB, 49 views)
File Type: jpg IMG_6595.jpg (28.1 KB, 42 views)
File Type: jpg IMG_6589.jpg (59.0 KB, 37 views)
File Type: jpg IMG_6586.jpg (39.8 KB, 39 views)
__________________
Why is there never enough time to do it right, but always enough time to do it over!!!
fred93 is offline   Reply With Quote
Old 06-12-2020, 06:30 PM   #19
fred93
Senior Member
 
fred93's Avatar
 
Join Date: Nov 2010
Location: SPRUCE PINE NC
Posts: 435
Default Re: 29 Tudor charging system question

Quote:
Originally Posted by ryanheacox View Post
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.
+++++++++++++++++++++++++++++++++++++++

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.
__________________
Why is there never enough time to do it right, but always enough time to do it over!!!
fred93 is offline   Reply With Quote
Old 06-12-2020, 06:55 PM   #20
chrs1961815
Senior Member
 
chrs1961815's Avatar
 
Join Date: Jul 2018
Location: Spring Grove, Illinois
Posts: 855
Default 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.
__________________
"The more things change, the more they stay the same."
chrs1961815 is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 05:34 PM.