k0ua
Epic Contributor
I'm betting on the Omni-present "bad ground"
Certainly a possibility. And easy way to measure that is a voltmeter between the negative terminal of the battery and the chassis of the tractor. while attempting to pull current. If a voltage is developed, that is NOT good. One way to pull current if you don't have a helper would be to turn on the headlights. Of course you can also just observe the headlights. If they seem normal brightness for a system not charging, then that alone is a good sign. If they appear dim or do not light, and the battery post voltage still measures near 12, then YES, a bad (corroded) ground or other connection is very likely.