98 cherokee overcharging

Recently my 98 cherokee classic has been failing to start when I turn it off especially after driving a short distance. If it sits awhile it usually will start back. The last time it done this after it started back (I stopped and started it back a couple of times) as I was driving home the checkguage light came on and the battery guage was all the way over to the right(overcharging). I turned it off and started it back and the hand was normal. I had the alternator checked it seemed to be fine, and had the battery posts and terminals cleaned. It hasn't done this anymore, I'm curious to as why this happened, and what should I have checked out know.

The not starting issue could be the Crankshaft Position Sensor; there are numerous threads about it.

The overcharging I'm not sure about.