Fluttering Ammeter

[Fred S]

Does anyone know what causes an ammeter that used to have a steady needle, to start fluttering? A friend said I might have a bad ground somewhere. But everything seemed to be working ok electrically, so I switched it out with another ammeter, and it ran steady. I put the original back in, and the fluttering resumed.

My instrument panel is chrome, and the ammeter has what appears to be an aluminum trim ring attached to the instrument panel. The spare has a black trim ring and its body didn't really fit in the aluminum ring, but I temporarily jammed in the spare body, for the test.

The original ammeter doesn't feel hot at all, and my battery is staying charged, so things appear to be working, except for the flutter.

I did a search and read where Tom Wesenberg said putting a drop of heavy gear oil on the pivot points would help dampen flutter. I plan to try that, but what causes needle flutter to start all of the sudden, after it has always run steady in the past?

[Chuck Sea/Tac]

It could be the amp meter or it could be the brushes bouncing in the generator?
If my battery is down a little bit the amp meter will bounce around until the battery gets close to charge, and then act normal. I'm curious what Tom thinks. I have a Peterson regulator that's got 31,000 miles on it. By the way.

[Tom Wesenberg]

Anything to disrupt a smooth flow of current between the generator and battery can cause the meter needle to flutter. Could be a loose wire, sticking or worn out brush, corroded or loose nut on the ammeter, generator, starter, etc. Jumper leads are great for bypassing suspected bad connections, and will easily let you know you have just bypassed a bad part of the circuit.

BTW, a bad battery, such as one with a short between plates due to junk in the bottom, can do this also.

[BILL WILLIAMSON]

Remember, the ammeter is NOT a REAL SOPHISTICATED design. I even sometime "shudder", when I see a CUTE Old Lady--LOL
Bill Flirt

[old31]

Bill your lucky.

For me there is no shuddering going on, not even for a cute young lady.

On a good day I might just barely get a "shud" but not a shudder

[Cool Hand Lurker]

Sponsored Links (Register now to hide all advertisements)

Originally Posted by Fred S

Does anyone know what causes an ammeter that used to have a steady needle, to start fluttering? A friend said I might have a bad ground somewhere. But everything seemed to be working ok electrically, so I switched it out with another ammeter, and it ran steady. I put the original back in, and the fluttering resumed.

Fred said that the spare replacement DID NOT FLUTTER so it has to be something in the original meter or in the connections to the meter, not all the other stuff that has been suggested.

[Dino's A]

Maybe it's a repo gauge like mine that "vibrates" when it recharges the battery back to full. But when they make a gauge for $9.00, what can we expect? I rather spend $40.00-$80.00 for a decent gauge but the vendors say folks won't pay that price.

[CT Jack]

Fred you said when you swapped the fluttering ammeter with another one it smoothed out. This says to me you have and internal connection problem within the ammeter. The solution is go get another ammeter.