I only drive my TJ on the weekends and I had to jump start it yesterday but I thought it was due to the cold weather lately. I drove it about 20 miles and all seemed OK. The alternator gauge was showing 14 at idle and highway speeds. I shut it down and had to jump it again. I headed back home and as I pulled back into the drive way the check gauge light came on and the alternator gauge pegged all the way to the right. I shut it off and the gauge is still pegged with the key out and of course it wont start. Any ideas before I do the usual battery and alternator test. Thanks.