Question about wiring marker light/turn signal

I recently put a 70 dart grill in my 72.

I can get the turn signal to work by itself and parking light to work by itself. But when parking lights are on and you try to put signal on it does not work.
I also noticed the bulb in the socket only lights up one of the elements (small one) in the socket. Both should be lit when lights are on and turn signal is on.....rite? Any help would be greatly appreciated.

Spez00@aol.com

516 359 7734

Thank you,
Chris
Author: admin