Instrument gremlins.

The turn switches are a known point of failure; the contact bits can break off and float around inside the switch assembly, and fail to make contact or make unwanted contact. They are available new; I would seriously look at just changing out the turn switch at this point.
One thing I failed to mention, and not on purpose, is the car had issues with that light when I bought it, before I did any work ( I forgot). Since than, as we already stated, the steering column, and everything inside it has been purchase from Norm's speed shop, and replaced. So everything should be new. Yet it still has the same problem. (So Back to I forgot.) The socket looks disgusting. Could it be the problem ? I know these are hard things to figure out over the computer.