GM-GMC: lights, light bulb sockets, gmc pickup

Question
I have a 1967 GMC pickup.
when I have my headlights on my turn signal lights will not work while my headlights are on.
What do I need to do?

Answer
My parents weren't even married in '67 LOL :)
It sounds to me like you have a ground problem.  Check your light bulb sockets to make sure one isn't shorting across to ground.  You may also try removing your signal bulbs one by one and rechecking to see if your problem disappears.  It may help you to narrow your search.
Hope this helps