Farmall B alternator/ammeter

But since the battery is going dead it sounds like also the alternator is not working. Could be it's wired wrong (the fact the ammeter does not show discharge as the battery runs down suggests this). Could also be the alternator itself is bad.

Best test would be to remove the alternator and take it to the nearest NAPA, AutoZone or local starter/generator shop. They can put it on a test stand and in about 30 seconds can you whether the alternator is functional.

If it's determined the alternator is OK then be looking for a wiring problem. And if not it's time to replace the alternator!

Sure the ammeter is even wired in and wired correct??? The Supply side terminal (only one wire there usually) connects to the hot ungrounded battery post, often by a wire from the starter switch or solenoid where the big battery cable connects. Then alllll lll loads like lights n ignition PLUS the alternators output connect to the ammeters other Load side terminal.

If the battery is good (have it load tested) but it runs down n requires re charging, sounds like theres a charging or wiring problem. I dont have much in the way of alternator troubleshooting tips, Im more into generators, but Bob M or Jim or the other Bob may have some troubleshootign tips on them. I simply see if the lights glow brighter from slow idle to fast RPM (means shes charging) or use a voltmeter on the battery AFTER Im sure all is wired correct..... ..

John T

Take care

John T

Put a charger on your battery overnight and see if it runs okay for a while the next time you run it. That'd be a tip. And, if you get a few minutes in between those extended returns you're workin' on, give a look at Bob's diagrams for the 12v setups. Strikin' me more and more as a good place to start.

We usually think of static discharge as an expenditure of electrostatic energy stored in our bodies and clothing, usually between a doorknob and the nerve endings of our fingers (''Ouch! Darn!'').

Static discharge can ALSO refer to the normal discharge which occurs in a Kettering ignition system with the ignition on and the engine at rest (or STATIC). A discharge occurs because the points are closed, completeing the path to ground through them.

Most original 6-volt Kettering systems on Farmalls show a static discharge of about 4 amps. If you have an alternator you probably have a non-standard ignition system (12 volt conversion), but UNLESS an electronic ignition has ALSO been installed, you should see a static dishcharge of some kind in the range of 2-4 amps.

So, turn on the ignition. If the meter does not deflect to show a slight discharge it is stuck, or (more likely in a 12-volt conversion of unkown quality) disconnected because the person doing the conversion didn't know how to make it read properly after the polarity switch (simple).

If the tractor does have points, it would NOT be running if the static discharge were NOT present. So a properly connected and functioning ammeter MUST show it.

If the meter has NOT been connected properly, and you didn't do the conversion yourself, be suspicious of the whole conversion job, as most people who understand these systems know how useful an ammeter is and will make sure it is in circuit and functioning properly before they deliver the job to a customer. Read the procedures and tips for conversions on these boards and elsewhere and take a good look at yours.

Remember, if the ammeter is disconnected, you've already found ONE thing you need to fix...