My 67 front and back turn signals don't work

['68OrangeSunshine]

As you may already know, the '67 is different from '68 and later thru '72 Chevy and GMC trucks. The Parking Lights on a '67 do not turn on when the headlight switch is pulled all the way out like on the later ones. They are not Running Lights. Sorry if that's not part of the issue.
They should blink on turns and in Hazard mode.
Troubleshooting Sequence:
Check out the bulbs.
Check the bulb sockets for 12 VDC.
Check your grounds. Clean and reattach.
Replace the Signal Flasher. [ The Turn Signal and Hazard Warning Flashers are identical -- swap them out and try that. Try a new one-- they do burn out.]
Check to see if all your connections are good. Connectors, splices, connection blocks. No broken lines, no burned junctions, etc.
Pull the wheel again and look at the turn signal switch assembly closely. Replace as needed.
[I had a similar gripe on my old '67 K/10 Suburban, one side turn signal wouldn't go --front right and rear left were out -- I think] When I put in a brand new T/S Sw Assy it all worked again, [the one I had painstakingly rebuilt from multiple junkyard and scrap parts didn't.
Good luck and have fun.