[techguy]

Just spent the last 2 months going through each circuit on my 72 targa and yes I too started with the reported double blinking.

Things to check:

-bulb sockets, I cleaned mine with a bit of sand paper often dirty

-replace the turn signal bulbs with new ones, often the base or side terminals become coroded or may be sloppy in the socket after all these years

-check the fuse for dirt/corrosion at the contacts

-double check all your gounds

My solution was to change the bulb after all that work with a new one and B I N G O. The new bulb had a nice tight fix and perfectly clean to boot.

Pete