ammeter

we replaced the voltage regulator and ammeter on a 1953 6volt ford jubilee tractor and the needle on the ammeter keeps bouncing back and forth what causes that, any suggestions.

You must not have liked the replies you got at the Ford Forum?

I replied with what I considered was an all-inclusive reply, ranging from operator perception, to the quality of today's parts, and mentioned what checks you can make on your charging system.

What did leave out?

"A certain amount of Ammeter "flickering" IS often "normal", and was when these machines were new.

Alternators with solid-state voltage regulators have been around so long there's a generation or two that doesn't remember how things used to be.

By nature, the old mechanical regulators are not as accurate/"steady" as what folks have grown up with, or if they did they are so uncommon anymore memories have faded.

Also, there used to be HUNDREDS, if not thousands of voltage regulators by part number, VERY closely matched to the generator they were intended to be used with.

Nowadays, a few generic units are sold as replacements for all those specialized units. That, in itself probably means regulation has become more "rough".

Quality, USA-made Ammeters were often "damped", made to smooth out fluctuations a bit and keep the needle more steady.

Not so much anymore with the cheap-made generic units sold today.

It certainly doesn't hurt to check that the generator's commutator and brushes are in good condition, check for loose connections, and verify that the generator AND VR are well grounded. Many tractors or vehicles used a ground wire between the "frames" of the generator and the voltage regulator to ensure that they are at the same ground potential, IIRC, yours should have one.

Beyond that the bottom line is, if your old generator charging system is keeping the battery charged, you can probably safely IGNORE it's imperfections."

I'm going to second what Wore-Out said about the commutator and brushes. My Fergy has 6volt generator and new ammeter bounced around crazy like, even though it wasn't charging the battery. Brushes were satisfactory but the commutator looked like it had been spray welded, all the contacts were shorted out to their neighbors. Quick clean up with super fine sand paper and a blast of air to clean any debris out -smoothed it out just fine.

JD

I've often seen that caused by worn down brushes,,,,,,weak or stuck brush hold down springys,,,,,,rough
burned or pitted commutators...or even carbon or oil coated commutators. Sometimes simply a good clean up
and shine of the commutator will help !!!!!!!

Other causes can be inferior or bad Voltage Regulators,,,,,,Burned pitted or carboned VR
contacts,,,,,,,,, Loose wiring connections OR POOR GROUNDS Or cheap ammeters !!!!!!!!!!

Try to clean up the gennys commutator and check wiring and for good grounds on BOTH the genny and VR

John T

Quoting wore out:

"Quality, USA-made Ammeters were often "damped", made to smooth out fluctuations a bit and keep the needle more steady.
Not so much anymore with the cheap-made generic units sold today".

________________________________________________

When I converted one of my WD-45s to 12 volt I installed a "no-name" ammeter I had lying around. The needle "bounced" as described. After I gave up trying to figure out why, I dug up an old S-W ammeter I also had lying around and, voila, no more problem. I think those cheap ammeters may have worked OK in the relatively smooth environment of a passenger car but not so well where the engine is not insulated from the chassis.
JMHO

Replace it with a voltmeter.

Generators don't use diodes because the output is DCV,
Measure output with an ACV. If you have a large AC voltage Like
John T said, the brushes may be worn causing a changing DCV.

Could be the regulator turning on and off too many times per
second. ..

Try a different Ammeter.

Let us know what you find out..

Best thing I ever did on my 6 volt IH was install a 12v alternator.

Some of us prefer them as close to factory original as possible -just saying.

What voltage and how much tension on the regulator spring ?

(quoted from post at 11:48:41 05/03/22) Some of us prefer them as close to factory original as possible -just saying.

Click to expand...

Nothing wrong with that.

This post was edited by Rich'sToys on 05/03/2022 at 08:56 pm.