turn signal help

[Goose]

I just had new tilt column installed in my '72 GMC. All turn signals worked for awhile. Now, the right front turn signal, the right front side marker light and right turn signal dash indicator do not work. The left side is fine. Where do I start? I do have a third brake light with a logic unit, but the left side is working fine and the right rear tail light is working fine. Do I have a faulty turn signal switch? Or what? Thanks for any help.