Early dart electrical gremlin???

I have a weird one. Thought I would see if any one has had this problem. My dart has virgin wiring. Not hacked up any were. Well the other day coming home from a cruse in I hit the switch on the floar to turn on my brights. Well the headlights went to bright no problem. But the speedo went dim, and the left and right turn signal dash lights came on with the little red bright indicator. Any one ever had this problem before? Every thing is normal with the headlights on dim. Thanks!!