1999 Honda Accord Electrical Problem

Own a '99 Honda Accord EX V6 AT 4dr with all the goodies, 78k. For past two years, the battery, brake and door ajar warning lights quickly (way less than a second) flash on and off at totally random times. Replaced the alternator and battery. Left head and tail lights have been replaced numerous times. Most of the time the old bulb is still operationally. Car has been scanned twice, once by my local mechanic and once by Honda dealer. Both scans didn’t return any codes. Help, please!