Hi I have a 71 Chevelle
When I turn on my left turn signal front left works, both rear lites flash, and on the dash the left stays on, if I apply the brakes both tail lites stay on and the front left directional is solid.
When I turn on my right signal right rear works, both front blink, dash both blink. If I applty the brakes right rear works, both front flash and the dash both lite are solid.
some one suggested replacing the turn signal switch in the steaering column.
Looking for some help!.

Before you replace anything, check and clean all front and back lighting grounds and clean lamp sockets and connections.
Check all bulbs are correct as well but it sounds like a bad ground

Thank you

I would also check the the multi-connector at the steering column.

This really sounds like a grounding issue. In some cases, because the brake lights are in the circuit you get a series vs parallel thing due to a bad ground where the light can be in series with the circuit rather than be grounded (shunt). That can cause all sorts of strangness.

I agree with Dave. Check all the grounds, including the ground contact inside the socket and the body.

Chuck