make sure you don't have the park and brake wires switched compared to the other side, but strange tail light problems are usually ground problems, make sure the ground is really good everywhere, light buckets to the brackets and brackets to the box, and it's worth adding a ground wire from the box to the frame, use lock washers that cut into the paint a bit - use an ohm meter to check from the socket case to the frame
note that the brake light and the turn light both use the brightest element and both go thru the signal switch, if one works the other should as well
Bill