why wont my car start just replaced aternator and battery?

You have weak battery,or bad connection/wiring to battery,or your stater is bad.

battery is brand new and so is alternator ?

Starter,then, if you know the battery wiring is good.

Starter changed that

2009 Honda accord will not start radio will not come on and can not shift out of park. Batterie is good. Car will choke but will not start. started relay is good. Any suggestions???

Same exact thing with my 2009 Honda Accord! I've read all kinds of forums and no answers. 3 batteries, 3 alternators, starter...it always starts with some dash light blinking on and off randomly...weeks go by it's fine...then a few dash lights randomly blinking...few more weeks and the ignition switch won't turn, next time the shifter is stuck, radio won't work, power windows and seats won't work, once it wouldn't go in reverse...gradually gets crazier and boom it won't start! My battery terminal always has a lot of build up, I clean it and it builds up again. Good, Interstate batteries...so I just replace the battery/alternator since it is under warranty and drive it for about a year. I've had several mechanics look at it. Best we can figure is it's a ground wire, some sort of draw and that's why the dash lights blink intermittently and it goes haywire.