bad crankshaft damper symptoms

I just bought my friend's old 94 5.0 for $1000 (135,000 miles). Love it, but timing sometimes seems off and voltage reading fluctuates a lot. At highway speeds, the engine is smooth and consequently the voltage reading is stable too. I know a bad crankshaft damper can effect timing, but can it have an effect on grounding? Or can it be causing slack in the accessory belt and causing the alternator to fluctuate. Any guidance from seasoned Mustang folks is appreciated.