Alternator light question

[psychoSEAL]

Yellow warning light would come on after driving say 15 miles. It did this a couple of times. Checked volts at battery with and without motor running and lights on. Everything checked out well. Replaced warn alternator belt. Made sure the new belt had correct tension. Starting the car now the warning light comes on immediately. Replaced voltage regulator, ran another ground wire to alternator, checked each wire and connector, replaced battery cable ends, had alternator triple checked. And still the warning/idiot light comes on and stays on after starting the engine. Car starts first time every time. I checked with Blas and we came up with a solution. Put a piece of black electrical tape over the light! Any ideas what could be causing this? Thinking about running new wiring from voltage reg to alternator to see if this could solve the light issue. Thanks!