Checking the ammeter

[kressej]

I went to Puyallup, 350 miles and ammeter charging rate was good, 6-8. While looking for an electrical problem, I replaced the ammeter and this one shows +2... How do I know what the REAL amount is?

Thanks.

[Drive Shaft Dave]

To check this I would use an analog VOM , selected to the 20 amp DC. Disconect the out put wire from the cutout, then connect one wire from the meter to the cutout out put and the other lead to the wire you took off. Start and run at fast idle and see what you get.

[Tom Wesenberg]

Connect the accurate meter as Dave said, and the black meter lead (-) goes on the cutout, and the red lead goes to the wire.

Is one of the ammeters an original?

[Mike V. Florida]

Sounds like a reproduction meter wired backwards.

[kressej]

I think my first one as original or at least over 25 years old. New one is a repro.

[Tom Wesenberg]

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Originally Posted by kressej

I think my first one as original or at least over 25 years old. New one is a repro.

If you look through the slot on an original, the brass parts are painted black. On repros they are unfinsihed brass, and easily seen through the slot.

[ian Simpson]

As somebody who augmented his apprentice wages by repairing many different electrical auto parts I would recommend anybody really interested in Model A electrical problems to acquire an Avometer. These are the premier VOM meters. Try ebay they are available. I got mine from a scrap dumpster at the local University. Unfortunately, they require an almost extinct battery for resistance measurement. Scan the internet, they are available, I got two from the UK yesterday.

[H. L. Chauvin]

FWIW:

Without mentioning names, within the last 18 months or so, a very reputable experienced & knowledgeable electrical engineer heavily involved in manufacturing Model A & Model T electrical parts warned me that today's foreign manufactured Model A reproduction ammeters are not at all reliable.

He reported that some work, some could be somewhat close to accurate, & some are so inaccurate that they are just a decoration in one's dash panel.

Anyway, I ordered & tried one of these new repro Model A ammeters. It fit my dash panel like a size 12-1/2 E shoe on a three (3) year old little boy with small feet.

Then, the needle fell out backwards several times, so without hesitation, in the garbage this new piece of junk went.

Immediately sent an email report to the reputable Model A parts vendor who reported that they would try to go to a different source if this foreign ammeter manufacturer could not provide a better Model A product.

Have no idea if this Model A parts vendor's "today's" repo ammeters have improved or not.

In the end, I re-installed my old original Model A ammeter which still works.

Moral of the Story is:

If you have an original Model A ammeter that works, do not throw it away.

Just one (1) Model A experience to share.

[Bill Goddard]

Drive Shaft,

Hooked up as you say you should be able to compare the VOM to the ammeter in the dash at the same time, right?

Also, why an analog meter and not a digital? Thanks Bill G

[Drive Shaft Dave]

Originally Posted by Bill Goddard

Drive Shaft,

Hooked up as you say you should be able to compare the VOM to the ammeter in the dash at the same time, right?

Also, why an analog meter and not a digital? Thanks Bill G

Yes,what reading did you get on the VOM? What Tom Wesenberg said.

[Tom Wesenberg]

And if the original doesn't work, they are usually pretty easy to fix.
Call Bert's for an original, or attend a national Model A meet and buy an original or a nicely restored original.

Bill, a digital meter is all over the place when around a running Model A due to the electrical "noise". This is caused by the ignition.

[H. L. Chauvin]

Comment on reply #8:

If one orders a new "repro" ammeter, one or more Model A vendors "may" have an improved ammeter since 18 months ago -- most of our most reputable vendors are always searching for better quality.

When I called the reputable vendor about 18 months to let them know the ammeter was junk, they said they knew it was junk; but, it was the best they could obtain from China & that they were still searching for better.

We saw this same thing happen a few years back when vendors could only get junk Model A tire tubes & junk Model A headlight sockets ......... then Bratton's found a supplier of "excellent" new tubes & "excellent" new headlight sockets.

We are all so fortunate to have several Model A vendors with integrity who own Model A's & are always on the lookout to better satisfy Model A customers & not just trying to sell junk to make money.

Plus if one calls a Model A vendor's "owner", (or ask for their experienced "technical expert" rather than a salesperson) .......... in advance ....... they will describe the quality of their "questionable" repro product & usually make honest recommendations whether or not for the customer to use their original part(s) or the repro parts.

Just sharing a few "good" experiences with Model A vendors to try to help.

[Bill Goddard]

Dave, haven't measured meter yet. Will report back when I do. Bill G