I just installed the wiring harness on my 68 for the turn signal and a new turn signal cam.

my problem is that i cant get the 3 bolts to screw in far enough to get that back retainer plate. I've tried everything. is there a trick?

Also, everything works ... except the left turn signal wont blink... it just lights up. all bulbs are new and plenty of good grounds. Any thoughts on this one?

This work for me just yesterday I was having the same problem. try turning your connection to the light bulb. Pull out the plastic connector and turn by 1/2. Hope it helps.