Turn signals not flashing

Inertia said
Dana hit it right on the head, vise-grip one end of a length of wire to the neg battery post, touch the other bare end to the actual metal bulb base, lites should work as normal.
With a poor/no ground at the bulb, the power comes to one filament of the bulb, but with no ground, power goes thru the other filament, (both filaments lit) back up that wire to ground at the indicator bulb on your dash.
Repair the grounds, test using that ground wire, in the trunk, vise-grip to the trunk lock striker in the middle.
Good luck.

Here’s is the wiring diagram from American auto wire. Iv checked it 2 or 3 times (Iv had this wiring harness on the car for 4 or 5 years now) and it is wired this way exactly. If I do the ground wire test and it works, should I run 1 separate ground to the headlight and 1 separate ground to the parking/turn signal bulb? It’s currently sharing the same ground