battery light comes on intermitently. checked alternator and battery , are good,

Just for a 'quick-check', NOT an all inclusive diagnosis, use a voltmeter, and observe the following- 1)Battery voltage with key OFF 2)Battery voltage with key ON 3) Voltage DROP, while cranking 4)Voltage at IDLE--NO LOADS ON 5)Voltage at idle with MULTIPLE LOADS (rear defrost/high beams/A/C with fan on high Report back with those actual readings if needed, for further assistance