I have a few questions for you which might narrow the problem down.
What vehicle model/year are you talking about?
Are you saying all the lights work except the front right turn signal?
The front right turn signal and parking light share a common ground in the circuit, if the parking light is not working also it could be the ground (check the ground), if it's just the turn signal, have you checked the light bulb to see if it's burned out?
Here is a electrical diagram to show what wires could be the problem if it's not the bulb. If you have any questions feel free to ask...good luck!