dr_n32

I have a Lexus ES350 /2008 with navigation system, I had an accident where the water radiator, the hood and the right headlight were replaced, the front bumper was only slightly affected but they changed it anyway. when the repair is finished I found out that whenever I turn the tail light and headlights on the 4 signal (hazard light) start to flash, when the tail light is off all buttons and switches works well. I send the car to Lexus workshop and after 1 week of investigation the told me that the Hazard button is shorted and it had affected another electronic card behind the NAV system (which works fine) and both have to be replaced. I search for the problem my self and came to a conclusion that the illumination light for the Hazard button could be causing the problem, I checked the Owner's manual and removed the fuse for (switch illumination), the lights went back to normal, now my question is can the hazard button be changed only or it has to be changed with the NAV system?is it really that the NAV system is damaged !! what shall I do??