Turn Signal Question, Please & Thanks

Hi, just need some insight please, to avoid fixing things that are not broken and buying parts that are not required. My 4way flashers work perfectly all the way around including the hood mounted lights, when the turn signal indicator is activated, all right side lights work no problem, when the driver side is used the light on the dash comes on but doesn't blink, either does the front park/signal, hood mounted light or tail light. I've checked the bulbs and all of them are good, I put in a new one just to verify and still no blinking. Would the turn signal flasher relay need to be replaced to fix this problem? or would one rule that out, because the right side still works fine.