'67 Dart - No stop lights, turn signals on but don't flash

Dana67Dart I have just ordered diagram from Classic Wiring, thank you looks easier to follow than thin black lines on 5 different pages in a manual.
The blinkers did work ok until the last journey; I can't think of anything unusual happening, no electrical work done. Sounds like this is going to be fun to sort out!
Mattax I'll look behind the dash, behind the flasher switch and try to trace to the flasher module; with my torch 8-)
The alternator is a one-wire, substituted along the way thru time before getting to me. The classic wiring chart may help me discover how that conversion was done. Ok to stick with the one-wire alt?
The ammeter will running (13.42V) was half way between vertical and max charging. This is where it always tends to, doesn't gradually come back to near neutral charge (even with minimal load on).
This is suggesting a significant constant load, a short?
Yep, in the stock radio location the PO has fitted aftermarket water temp and oil pressure gauges.
When the fuse blow, I had pulled the light switch on full, two clicks.