ok i have an 03 sedan with stock nav when its cold out the screen does not go on(blank) nav screen seems to work fine after car warms up?..is this a comon issue? like do i need to let the inside of the car get warm for the screen to work?..the naviagtion dvd player works fine when i turn car on when its cold but screen does not...any help would be appreciated

 

Not an unusual problem with LCD screens at low temperatures. My 08 screen is not blank but is much dimmer for a short period of time until the car warms up (or the screen does from backlighting).

You could be suffering from both issues (since yours is blank), that of the LCD and that of the backlight. It may be that the backlight is not coming on at low temperatures.