Ammeter question/problem

[loubob]

While working on the dash, I damaged the ammeter to the "point of no return."

Ordered a new cheap repro.

Installed it and put wires on the same as they were on the original ammeter.

When started the ammeter showed discharge so I switched the wires.
This time when started ammeter showed a charge.

Went for a drive and the ammeter was pegged @ 20. The original one always stayed at 10.

What am I 'missing" in this equation?

Loubob

[700rpm]

Repro ammeters are notoriously inaccurate. Call Bert's in Denver and see if you can get an original.

[jeep44]

Are there any repros that are any good?

[ericr]

wasn't there some talk recently on the Barn that a quality repro is in the works?

[Charlie Stephens]

Originally Posted by loubob

While working on the dash, I damaged the ammeter to the "point of no return."

Ordered a new cheap repro.

Installed it and put wires on the same as they were on the original ammeter.

When started the ammeter showed discharge so I switched the wires.
This time when started ammeter showed a charge.

Went for a drive and the ammeter was pegged @ 20. The original one always stayed at 10.

What am I 'missing" in this equation?

Loubob

I have read the ammeters for the Model T had the terminals reversed and that may be what you have. I would worry that maybe the ammeter is accurate and something else is wrong. You should resolve the 20 amp issue before you drive the car or you will have more things to replace. Does the ammeter show about -10 amps when the car is off and you turn on the headlights? I think I remember hearing a while back that someone was working on a high quality reproduction ammeter but I don't remember who or the estimated release date.

Charlie Stephens

[loubob]

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With ignition off, ammeter shows '0'

With headlights on shows -10

Blowing horn with ignition off shows a negative reading.

I will call Bert's Monday morning.

Will also check with some of my fellow club members.

Thanks.....Loubob

[Charlie Stephens]

Originally Posted by loubob

With ignition off, ammeter shows '0'

With headlights on shows -10

Blowing horn with ignition off shows a negative reading.

I will call Bert's Monday morning.

Will also check with some of my fellow club members.

Thanks.....Loubob

The ammeter passed these tests. I am more convinced that you may have a problem elsewhere causing the ammeter to be pinned. Can you borrow an ammeter from a friend or find someone with a meter to check it out?

Charlie Stephens

[loubob]

Car has been running fine.
Ammeter has always been charging at +10-12 while driving.
Ammeter replaced and now there's a problem.
Will get another ammeter this week and will see if charging issue remains the same or drops to where my original was running.

Loubob

[Tom Wesenberg]

If Bert's doesn't have a restored original, check ebay for phoncon selling a restored original ammeter. He used to post a few for sale, and they were very nicely done.

[Mike V. Florida]

Originally Posted by loubob

What am I 'missing" in this equation?

An original ammeter!

[mcorrell]

I have an older USA made repop 30A ammeter. My car shows 10A charge running with lights on and 20A running no lights. I drive with lights on always for visibility to other drivers.

[loubob]

Tom: Thanks for the Ebay seller info.

[loubob]

mcorrell: Is it safe to run @ a +20 charging rate? I'd think that was too high and it could/would cause damage to the electrical system. I've only been into A's for several years so I could be wrong.

[mcorrell]

You could boil the battery out quickly if you don't run the lights. At idle there is a slight discharge with lights off. As mentioned I always run the lights. We had a couple in the area that were killed in their early Ford pickup when they were rear ended by an inattentive driver.
Another thing is that all of my trips are short...less than 5 miles. Lots of starts.