The pigtail off the positive battery cable should have a fusible link attached to it. I'm not familiar with the 67 wiring layout but on my 70 the pigtail/fusible link goes to a junction block on the rad core support. Check the other end of the fusible link to see if you have voltage. There is also a fusible link in the harness near the main splice. Look at the wiring diagram in the link below. Start at the battery and work towards the fuse block to see where you have voltage and where you don't.
http://www.madelectrical.com/electri...evymain1.shtml