Is my alternator broken after mudding?

I went mudding yesterday in my 94 ford explorer XLT during lunch at school, leaving mud on the engine, and when i drove home from school, my battery light was on and my battery was at halfway. It stayed like that my whole trip. I charged my battery last night until it was full and drove to school today. The gauge changed slowly from full to half and then back to full while i was driving. It did this on my way to and from school. When i got home, i washed all of the mud off my engine and let it dry. I turned my car back on and the battery was at halfway still. I just put it on to charge again, and the charger didn't say it was full. Is this my alternator that is shorted out or broken? Or could it just be a problem with the gauge? How much will it cost in Utah to get the alternator fixed?

If your going to go mudding, you need to check all electrical connectors. You need to weatherproof them to keep dirt (dry mud) and moisture (water and mud ) out of connections. You probably didn't do this beforehand so now you have bad connections. Clean them up and you'll probably be OK. You also might protect wiring, hoses, lines from off-road damage.

If you were jarring around it is more likely you simply need to unplug the wiring harness at your alternator and clean the contacts and replug it in.

Alternators take time to charge a battery so short runs here and there won't do a thing. Make sure you have enough liquid in the battery then charge it on a trickle charger. The alternator could be on its way out they do this before they actually fail. 140 bucks for the larger 130 amp from O reilly then they will give you 35 bucks back when you return the old alternator. If you know how to remove two or three bolts a wire harness and a wire bolt a few hours to remove and replace. I've replaced alternators in less than 15 minutes if everything plays nice.

Idiots who play in the mud buy more parts.