The fast idle solenoid wire is dark green. I got an AC wiring diagram for the 68 firebird; it shows everything but this black with one orange stripe wire that comes out of the passenger side of the wiring gutter on the cowl. (8point - This 68 diagram shows the #12 wire that has an orange stripe top AND bottom, goes to a 30 amp fuse link and then on to the "Bat" terminal of the horn relay. That's the high speed fan fuse link. Not sure if that's the one you're looking at...but it's very long.)
