Farmall 450 Amp Meter

I have a 1957 Farmall 450 with a 12v negative ground converstion using an 1 pole alternator. The conversion was done by the prior owner. The Amp Meter does not seem to register anything. I have checked voltages on both sides of the amp meter and both sides have 12+ volts. Using the volt meter, the alternator is charging. I have installed other amp meters and none seem to work. Wiring appears to ob okay. Question -- why does the amp meter needle not move under and condtion load, charging, etc.?

My 450 was converted to 12 volt and the needle doesn't move very far either unless I run the battery down a ways. It could be the guage is sticky. I don't think mine ever pulls more than 5 amps at best.

Thanks for feedback. In other research someone provided the following comment: "RARELY DO YOU GET ENOUGH CURRENT ON A TRACTOR TO CAUSE AN AMP METER TO MOVE". Maybe nothing is wrong. It will be helpful to see other feedback.

Is the ammeter wired correct?? Battery on one (supply) side and loads (lights ignition) plus alternators output on the other side????

John T

I will check connections again. Some easy to view and others in home made harness and I will need to trace with meter... I assume that if the wires are on the wrong sides, the needle would still move, just in the wrong direction.

If the wires were swapped side to side it would work but register bass ackwards however the alternators output and loads must all be on the opposite side the battery is wired to.

BOTH sides are hot if theres hot voltage on either side cuz its basically a near short circuit across it.

I suspect the alternator may be wired getting direct to the battery verus its current having to pass thru the ammeter as it should. The ammeters output wires to where the wire down to BAT on the VR used to wire

Of course the needle may be stuck??? Pass a magnet over it and see if the needle deflects??

John T

What voltage are you seeing from the alternator ?? It must 13.5 volts or above . Normal Delco 1 wire alternator voltage with a full charged battery is 14.2-14.8 volts.

If the alternator is putting out 13.5 volts or more, and the ammeter still does not indicate charge, I suspect the ammeter is wired wrong.

One battery post must have nothing but the battery connected to it.
The other ammeter post should have any accessory load such as ignition or lights, plus the "BAT" output wire from the alternator attached.
The ammeter's only job is to indicate power flowing into or out of the battery. To do this, the battery must be the only thing connected to one ammeter post while all other load and charging connections must be on the other post for it to indicate correctly.

If the one wire Delco alternator does not produce 13.5 or higher voltage, it may have lost it's residual magnetism that allows it to self excite.
To Excite the field and restore the residual magnetism, touch a wire from the #1 blade terminal at the rear edge of the alternator case, below the rectangular regulator plug socket.
You will see the numbers 1 and 2 cast into the alternator case below the plug socket.
With the tractor running about 1/2 speed, touch a wire from the big "BAT stud on the alternator rear to the #1 alternator blade terminal. It only needs to touch for a moment. The field magnetism will be restored and the alternator will now charge a normal 14+ volts.

Normally you will not have to repeat this excite procedure unless the alternator is worked on or the tractor sits unused for a long time.(months or years.)

Also make sure the fan and alternator belt are tight. I have worked on several h-450 IH tractors where the no charge problem was that the fan belt was too loose to turn the fan / alternator fast enough.

That is false, with an alternator, you will normally see 30-60 amp charge for atleast a few seconds after a start. As the battery reaches full charge, the ammeter reading should back down to 2-5 amps charge..

Sorry , I made a typo in the post above . It should say ."one Ammeter post should have nothing but the battery connected to it.".

Probably the Alternator and battery are are the same ammeter terminal. Battery charging current won't show . Only will see maybe ignition current and lights.

Well, I think the case is solved. You folks collectively hit the nail on the head. John Hagen and John T identified the specific issue, the load wire was on the wrong side. Now battery is on one post and the load and alternator output is on the other post. Amp Meter reads as expected. After exciting alternator the voltage across the battery reads 14+ and most any RPM. I suspect that amp meters can and do have a personality and may be sticky also.

I want to thank everyone for advice, much appreciated. You can view the tractor anther farm equipment on my website --- www.chaselinks.com.

My farm is in northeast Connecticut and has been in my family since c1860. I grew up on the dairy farm but after college I moved away for 40+ years working in corporate America in the global technology business. Now back on the farm as a retired hobby farmer raising horse hay (sq bales) and geese/ducks, as well as a tractor enthusiast and hack mechanic. All much more rewarding than the computer technology business.

Thanks for telling us what worked, that way all learn and gain from the experience.