Have you had any problem with the Hazzard fuse blowing? After the switch, they use the same run. Try lightly moving the harness for and aft along the drivers side under the sill plate. Have you ran any screws into that area? check the area where the signal harness come out of the column and check to see it is not pinched anywhere in there. The column rotates in that area and can wear through or pinch the cabling. CHeck that the fuse socket is clean (corrosion there will blow fuses).
Just some thoughts without being there.
Dave