I have a dreaded problem with the instrument cluster lights (speedo, tach, oil pressure, temp, volt) on my 73 mustang. Turn signal indicators work as does the high beam (red mustang) indicator. Map light, door open lights, stereo, heater all work. I have replaced the headlight/dimmer switch with no success as well as all the bulbs in the cluster and 4 amp fuse. I would order the printed circuit board replacement if the signals and high beam indicator were not working as well but its a pricey guess. Any thoughts were to look next?