My turns signal and Emergency flashers work fine as fare as the headlight is Off, as soon as i turn it ON, the driver side Turn Signal latch ON and the turn signals and the emergency flasher won't work and won't respond untill i turn the headlight back Off then everything goes back to normal.
my turns light stop workinmg as soon as i turn the headlight ON on 2007 Honda Odyssey
Do the signals work when just the parking lights are on , not the headlights?
Has it ever had any body work , or have the front signal bulbs been changed recently?
it could be a bad ground not allowing enough ground for the turn signals to work with the headlights using up the available ground. you need to figure out whether you can losing the voltage or the ground to the turn signals. it could be a failing multi=function switch as well.