I replaced my battery on my 2000 TJ last week because the old one was going out. I noticed when I first started it up after putting new one in, the battery gauge was only reading around 10-11. While driving and and using only my radio it dropped to zero. But the radio was still playing and it was still driving normal. I went back home just in case it wouldn't start back up and turned it off. Then it started right back up for me at about 10-11 on the gauge. Drove it a few miles and it did the same thing but continued driving and everything working like normal. Except for the gauge of course. And one other odd thing, while driving the mileage indicator shot up to as high as it can go and immediately down to zero, then back up to about the mileage I was going prior to the weirdness. During this it continued driving normal and has been starting right up on first crank. Any idea what this could be?