magnmike,
I looked at the only wiring diagram I could find. I was for a '54 truck, so It might not be accurate for your truck.
There is no common connection between headlights and turn signals. Turn signals are brake lights that utilize the flasher to blink them. If you have brake lights but no turn signals, this would indicate a flasher problem as 3B mentioned.
If everything worked before you installed the 12 volt battery, and it doesn't work now, it would appear to be a fusing problem. You have stated you replaced three blown fuses, but it still doesn't work.
Merely installing the battery wouldn't blow the fuses unless you energized that circuit. The brake lights connect to back of the headlight switch, but only as a connection point...they aren't switched.
Something is rotten in Denmark..keep looking.
Stuart
