After yesterday's success I put the battery charger on the Cub Cadet overnight, today I went out to see if it would start better than in the past considering all the electricity was getting to the starter/generator. I hit the starter and it cranked over much quicker than before but after maybe half a second of cranking I was "rewarded" with smoke and burning plastic smell.
My tractor has an ammeter which has never worked. As part of the cleaning I did yesterday I cleaned the terminal where the ammeter is connected to the starter switch. It turns out that the other side of the ammeter was connected to the L terminal on the voltage regulator. This is WRONG, it should be connected to the BAT terminal on the regulator. Fortunately the wiring on the Cub is pretty heavy so all I got was a couple melty insulation spots which I fixed with tape.
I went on to make up the last heavy wire which goes from the switch to the starter/generator so now the whole path to the starter/generator is 8ga which is very heavy for a garden tractor and I'm confident that it'll never be a problem.
Unfortunately now when I turn the key switch on the voltage regulator clicks and the ignition coil loses voltage. Interestingly if I turn the switch just part way it doesn't happen and the tractor will start and run. I *think* this means that when the ammeter was wired incorrectly it forced the key switch to take full current which I *think* is allowing the switch to short out when turned all the way. I need to pull the switch and see if its something I can fix or if I need a new switch. Fortunately 2 position switches aren't terribly expensive.
The ammeter STILL doesn't work because although it doesn't cause a short anymore its still not wired right. Right now its wired from the hot side of the starter switch to the BAT terminal on the regulator but the starting switch still has a line from the hot side to the BAT terminal. To work correctly an ammeter has to be inline between the hot side of the starting switch and the BAT terminal where mine is currently parallel. The wiring on my tractor would work okay for a voltmeter except it'd drain the battery since it can't be turned off. A volt meter should really be to the switched side of the ignition switch. So to fix this I need to disconnect the original wire from the starter switch to the BAT terminal which would just leave my ammeter.
At some point I really need to re-wire the whole tractor. Another problem I worked on was that the wire from the ignition switch to the coil was cracked badly. This wire wraps around the back side of the engine and is bad on my Cub Cadet 72 as well. I used a weatherproof butt connector and a length of green wire which should have been black. If I feel real bad about it I'll blacken it with a paint pen. Of course later on I found a spot thats cracked beyond where I'd fixed. I've also got the old link to the starter/generator just hanging out. I debated cutting that wire off but left it. I'll be on the lookout for some cheap wire loom to build my new harness around at which point I'll buy the correct color wires and redo things right.