Why do I need to hold my blinker down in order for my car to start

What is your question?

I have a 2006 Nissan Altima that I just bought off someone it runs fine theres no issues but I'm curious to know why I need to hold my blinker down in order for the car to start if I don't hold it down the car will not turn over and start. When i bought the car the person told me i had to hold the blinker down while starting the car. New battery and starter