Re: battery light?
I had the exact same thing happen and it turned out to be my positive cable harness... the one that connects the 2 batteries and runs down to starter. I went through all the TS & that is what it ended up being. Alt. was putting out fine, put new cable ends on, all sorts of things before finally nailing down the cable harness. They are notorious for causing trouble. It is very likely the reason I went through several batteries as well.
97 HD Supercab LB 4x4. E4OD w/"mini shift kit" & Schaeffers synthetic, Tru Cool cooler, 4:10's, 33's on Weld Typhoon wheels, Gauges, Swamps stage 1's, Swamps IDM, TS 6 pos chip with Swamps tunes, Tymar intake, 3" DP, 4" exhaust (had to keep cat). Weather Guard toolbox, GPS, Billet grill.