Troubleshooting an alternator, Three videos of the Roadrunner song, One of Turn Your Radio on, and other rambling

My "new" tractor has been a continual source of frustration. I have gradually dealt with the problems, whittling my way down by either ignoring or fixing issues. Along the way I've put over 200 hours on it. Time for an oil change!
The alternator is the latest frustration.
When you turn the a/c fan on to high the voltage drops to 10 volts. If you don't notice it will fry the a/c compressor clutch. The a/c clutch is a magnetic clutch. Low voltage in hot weather results in slippage which you can't hear in the cab...with the radio on...

Or...

Or...

 Or..

But I digress,
In fact I have completely lost my point...
Tractors, Alternators, problems, yes...
First we installed a 90 amp alternator, then tried a smaller pulley. The smaller pulley helped.
I am wondering if it is the voltage sensor wire turning off the alternator too soon?
Of course the tractor is hooked to a baler ten miles away.
My little helper asked for the day off as his son is having "relationship" problems and made a comment on facebook which was interpreted by my helpers crazy ex-wife as a suicide threat. Crazy ex-wife called the cops. Of course the kid probably wouldn't have "relationship" problems at age 13 if his "crazy" mother would have been just a touch more careful about bringing guys home to impregnate her... But, that just sounds harsh doesn't it... Has nothing to do with alternators...

Here is the link: Click here, it explains all about delco alternators. Very useful info, plus you got to see three different versions of the song "Road Runner."

Update at 6 p.m. when I should be making pig feed.

I found that the sensor wire was connected to the power wire on the back of the alternator. This causes the alternator to shut off too soon as it reads its own voltage. So, I moved the wire to the battery input on the starter.
This sort of helped.
So I check the voltage at the starter. 14 volts. Then I checked the voltage at the cab, 10 volts with the radio on... and the a/c on high.
So I started looking for heavy gauge wires that could be pinched or have a bad connection. I found the main cab power wire under the fuel tank, soaked in diesel, with a glob of melting electrical tape. Under the tape the bare wires were just twisted together.
So I put in a crimp splice and covered it with shrink tubing and then that plastic insulation in a can stuff. I should have soldered it but we really needed to cut hay. My little helper came in to help me despite the family crisis.
I now have 13 volts in the cab with the radio on... and the a/c on high... goin' 17 miles an hour, with the radio on... You have to watch the video to understand. The Bo Diddly one is the only good version of "Roadrunner."

I also changed the title because the only person that actually cared about Delco Alternators was Ralph Goff! Pretty funny, only like five page views today...