2003 Honda Accord Car dies when braking

Get the alternator and battery checked out then comeback

battery voltage 12.75, running 13.5.
also have same issue when turning on headlights.

Battery and Alternator running voltage looks good-Now for the stalling investigate the vacuum hose/check valve/brake booster if its leaking a leak here will affect idle speed also check the PCV and EGR valves. Also check the turn signal flasher.

idle speed is 700 rpms.
dash lights go dead, seems like you turn off key momentarily. dad is a electrician and he seems to think electrical more than vacuum

Why does the car stall when pushing brake pedal or using turn signal

This is the catch-for electrical problem involving the exterior lights-brake and turn-Since he's electrician should be able to troubleshoot it-

thank you ...but since my dad is an electrician he knows to stay away from it.
Im taking it to the dealer tomorrow and ill let you know what it was.
once again thanks for your time

the problem was that the ground wire on the engine block was loose. the mechanic cant explain how it got loose but after getting the screw back to its original position the problem is gone.

Thank You for coming back and letting us know what the fix is.