In my 1986 Mustang GT the blinkers/signals on the outside of the car all work correctly and I can hear the signaling sound inside the car. However, the little left and right arrow indicators in the dashboard panel are not working. Any suggestions on what the likely cause would be and where to start? Not sure if it could be related to the flasher relay or not. I was thinking the bulbs could be out but weird if both were out left and right. thanks!