Originally flashers are activated by bulb loads. they are allways energized, but untill bulbs are not sucking load the flasher won't be activated. I guess getting the led conversion, you got the electronic flasher for it, but STILL the signal should be there for them just like originals did

Of course hazzards are feeded from BATT source, while turning needs to get the ign key in ACC or RUN.

Assuming by your screen name you are working on a 72, you can check the red wire arriving to turning switch plug down the column. Put your ign swith on ACC and check for power on turning switch plug. It must be energized. If not, you have a damaged flasher or even unexistant one.

If you have power and still don't get turnings working, it could be the switch damaged... or bulbs

P.S.: the 3 ways flasher there as mentioned is for the ign switch courtesy light on column just at a side of the hazzard knob. It will turn on that light for around 8-15 seconds after get the dome light on and off ( doors opened or dimmer dome light on )