I have a 2000 mustang my issue is that my blinkers were not working and i replace the flasher relay and now my blinkers stay on(not flashing just on) and my hazards will not come on.

 

Replaced the fuses and the multifunction switch and blinkers just stay on and if i press the hazard switch the blinkers cut off.

 

Wiring issue of some kind, sounds like. Although if you have replaced the lights with incorrect ones (say the LEDs people like to do) that may be a part of it. Put in the real lights the car came with if that's the case.

Also there's a flasher in that car. Perhaps replace it.
https://www.oreillyauto.com/shop/b/l...0/ford/mustang
https://www.americanmuscle.com/raxio...ter%20console.

Hope that helps, and welcome to the forums!