Silvr, my truck is an 81. The lt.blue and lt.green wire coming out of the firewall going over the break booster and down to the tranny controls my backup light switch. The only thing different is that my blue wire is dark blue(maybe cuz mines a 4sp). The pink and black wire coming off of the panel go up to the gauge cluster. Mine doesn't have the connector off of the steering column.
I was looking through my Haynes manual and none of the wire schematics show a lt.blue and lt.green wire from the firewall or your panel box setup. I even looked under the 6cyl schematic just in case it was converted but got nothing. Good luck!