Ammeter not showing charge

I then cranked it back up and the ammeter started working again, only, it was showing a charge all the way over to the right on the gauge. It then fell back to just to the right of "0".

I just started the tractor again, and the ammeter is not working again. Does anyone know what could be the problem? The alternator is new. Could it possibly be the coil?

Thanks in advance for anyone's help.

Instead, check the charging voltage with a GOOD digital meter or and analog meter. (Cheapy digital meters often "freak out" when used on an old tractor, due to electrical noise from the ignition and charging systems.)

You need to see 13.5 Volts to 14.5 Volts (or possibly slightly more), if the alternator is charging properly.

It does not take a good alternator very long to charge a good battery, and what you're seeing the ammeter do MAY be normal.

Virtually nothing in common with the ignition circuit and the charge circuit except the battery, and some copper between them.

I'd look for a loose connection.. either at the alternator, or at the ammeter, etc.

An initial high charge that tapers off to a ver low positive charge is normal. If it shows a discharge.. that is not normal.

Do a votlage test. Measure voltage at the battery with the tractor off. Now measure voltage at the alternator charge stud with it running.. Should show up to 12.6 on the battery with engine off. With engine on, alternator should show 13.2-14.7 preferably in the 14's though. Now.. if you show a good charge voltage ont he alternator.. check the battery while running. should show the same voltage that your alternator showed. if it doesn't you have a bad connection.. or bad wireing.

Ammeter is almost bullet proof.. they rarely open...

Soundguy

A 1 wire alternator will attach to the same point that the batt connection from the VR would have connected to... the ammeter.

Your fo-4 has a schematic of the oem wire diagram.. just forget about the vr, and genny. Besides.. having a wire diagram doesn't sound like it is going to help much.. pretty much the ignition and charge circuit are seperate circuits, tied in at the ammeter for the owner to see what the battery state is... Sounds like you need a new wire harness.. and since you are on a 12v conversion.. i Don't know of a pre-made one out there, so you will be cobbling up one or modifying an oem one.

Here is a link to one for a 3 wire job.. just ignore the p1 / p2 wires. Also.. don't wire your headlamps thru your ignition switch... instead wire them from the same point the ignition switch gets its power from.. which on that diagram, is the bottom pole on the wire block / out leg of the ammeter.

Also.. before you start buying parts and blindly throwing them at it.. do some checks with a VOM.. I've seen them from 4.99 to 9.99 or so.. better/cheaper than buying an alternator on a guess.

Soundguy

Thanks
PT

As i said before.. a 9.99$ volt/ohm meter would be the cheapest route, and probably save you time and hassle...

Soundguy

Like I said.. the chargeing and ignition systems are all but seperate systems.

At very worst, if the coil secondary was shorted to ground, the tractor wouldn't run.. but even with that.. there would only be a 3 or 4 amp draw.. as if the key was on and points closed.

Also.. if the primary was shorted to ground, the tractor would not run.. and the wire tot he coil primary would burn in half in less than a minute..

In both cases.. no tractor ignition.. same with an 'open' coil... Looking at that.. yes, if the tractor won't run, then yes.. the coil could keep the tractor from charging...if the tractor will run.. then no.. the coil has -0- to do with the charge system, like I said in my previous post.

Sounds like you really really want to spend the 15$- 30$ to change the coil since you've asked about it twice, in connection with the charge system. If that's what you are aiming for.. go change the coil.. then come back, and fix that unrelated charge system problem...

Soundguy