I recently purchased a '73 Charger and had the bad steering box replaced. Car also had a tiny 13" wheel and had replaced with a repo 15" tuff wheel. Also had no left turn signal. Right worked fine as did the flashers. Now, no signals, no flashers and more importantly, no brake lights. Is the steering assembly harness bad and would that affect the brake lights?

I hate tracking these problems down. Years ago, a similar problem in my '74 Satellite traced to a shorted trunk light wire.

Replace the turn signal switch assembly. All those functions you're having trouble with go through that. Get a good quality Mopar one, not a cheap replacement from the local auto parts store.
attaboy

Thanks, I'll go this route.

If you want to diagnose it www.mymopar.com has wiring diagrams for the colors to work on and a parts store circuit tester, the one w the alligator clip on one end of a wire and a light w a thin metal pointer on the other end is the one to use & is only several bucks. I'd check for fire on the particular color wires in the pull apart electrical connector(not the one for the ign but the one for the turn signals/brake lights) keeping both halves still connected & see what you find for opens. If you do purchase a TS harness ahead of time I'd plug it in the connector outside of the column before undoing the steering wheel.