2003 Honda accord won't start
 

My car wouldnt start once in awhile. Got a new battery, then a starter then alternator still won't start. Started once after changing each part then everything goes off on dash. Car kept driving got home now won't start again. Red lite over radio flashes, green key lite flashes on. When I move gear shifter dash flashes on and off. Please help.

Any codes? Possible starter relay or switch.