Classic/Antique Car Repair: cadillac starter, slide switch, hot wire

Question
My son-in-law had a no start problem in my 1970 Deville while out of town. Someone where he works "diagnosed" it as the starter, and supposedly bench tested on sight. He pulled the starter and I told my son-in-law to take it to NAPA to be tested. It was fine. My son-in-law reinstalled it. No start. When I drove up there, the first thing I discovered was the body was 12 Volts hot. He had connected the Hot cable from the battery to ground instead of the solenoid. I had it towed home. With the starter disconnected I still had a hot body. As I started disconnecting everything back to the battery I discovered that my alternator case was now hot, so I got a new alternator. I haven't put in it yet, because I'm back to the no start problem. Since I didn't take out the starter I wasn't sure which of the placement of the two small wires on the solenoid. I took apart the starter to see which terminal activates the starter, and tested to see which wire was hot in start position. It was then I discovered that the original no start problem was that the ignition slide switch needed adjustment. I attached the start-position-hot wire to the the solenoid, but my concern is where the other wire leads to. Most of my experience is in Mopar, but I'm assuming that I don't need the alternator installed in order to start the car. I took apart most of the harness tracking down the hot body problem and found several wires on the left side if the block leading nowhere. There was apparently something installed that no longer is there. There was one wire with an eyelet near the coil. My son-in law claims the guy didn't disconnect anything topside when he pulled the starter, but that wire concerns me, if the other solenoid wire was supposed to go to the coil.

Answer
The other wire is an ignition hot or a 'run hot' wire. Test your other wire and you will find it is 12v hot with ignition on and dead when it is off. In most cases, it does attach to the positive pole on the coil.

May I suggest a tool that you will find very useful. An inexpensive Ohm meter. You can get on these days for about $5 and it is an easy way to see "which wire is what" by letting you know you have both ends of the same wire. With this ohm meter, you can quickly verify that each wire goes where you think it should.

Don't concern yourself too much with the extra wires in a wiring harness. That is common. The auto manufacturer covered their bases in case the purchaser wanted a towing package or extra stereo amp once the car was sold.

Also, be aware you may have gauge problems depending on how long and extensive the voltage reversal was in the car.