I just boughta 68 coupe and took the guages out to replace the left turn signal indicater bulb and painted the guage carrier while I had it apart.

I noticed that there were 2 screws on the printed circuit board that i assume were grounds and tightened them up. The left turn siganl bulb was not burned out and is now working after tightening the screws.
After putting it back together, whenever the headlights are tuned on the turn signal indicators light up steady, but blink when the turn signal is turned on. Is this normal?

Also, when the headlights are turned on, the fuel guage drops below empty...I am not sure if it did this before or not...

 

check all the grounds going to the dash and the guage cluster, and also make sure the light switch is grounded. Make sure there is no paint were the grounds attach to the guage cluster after painting