help me buy the right piece-turn signal

[pestwagon]

newbie here- All four of My 66 truck's turn signals all work but I need to hold the turn lever down firmly to keep them blinking left, if I don't then I can hear the relay switch click on/off but no left blinkers light up. If I push the lever up it blinks right, and I dont need to hold it in place. But it doesn't return to normal with either a left or right turn, so do I need a $10 cancelling cam? Or a $95 turn switch? TIA...