Take a look at these .pdf diagram pages from the '68 Diagnosis Manual. I noticed the difference of the '68 Wiring Diagram to my '68 when I was replacing the AC's high speed blower) inline fuse and holder. Researching the Diagnosis Manual I realized the discrepancy between the references. Note there are other errors in the SM too. Here's a photo of my wire to the blower motor too. Just don't forget that dedicated 30A fused line from the alternator.
That said, my AC has never worked well. First, it needed a lot of work during the '68's daily driver years ('69-83) and second, it is just not efficient enough to truly cool the car when it after it sat in the sun all day with that thin black convert top. It was find when I pulled out of the garage in the morning but never cooled down on my commute home after work. I drove it top-down mostly when the weather permitted.
