Running Lights Blowing Fuse

[Austinr98]

Just purchased a 1995 1500 ext cab 5.7l. My problem is about once every three days when I turn my lights on it will blow fuse 9 eliminating tail lights,dash lights exec. Last night I turned on my lights, I heard a loud pop from the area of the fuse box and no dash lights, thought the fuse had just blown again, but this time my charging warning light came on, now my alt is only putting out 12 amps, and replacing the fuse does not fix the light problem anylonger. Any and all ideas would be greatly appreciated.