The intermittent charging problem was the OEM alternator. I did replace the battery under warranty first. It went bad and wouldn't hold a charge anymore but I think the old alternator messed it up. I still got the occasional warning light even with the new battery. After replacing the alternator, which was almost 13 years old, no more problems. I did blow some air around that sensor too, lots of sand and dirt.
I found a used matching cluster on ebay and installed it yesterday. Everything works now but I'll still have to take it in to fix the odometer reading. Also, this cluster was a few years younger and the other Liberty had that tire pressure system. I'll have to try to get that light/sensor turned off but otherwise I have a working tach/speedo/gas/temp gauges again.
