Rule #1 - Always check your grounds first.
When things that are seemingly unrelated fail at the same time, ground is always the prime suspect. Keep it simple at attach one issue at a time. Look for your dash grounds. I'm not sure but someone will know whether a 68 has a ground strap on the steering column or grounds through the dash mounts.
It's also important to know all the components that are or are not working (radio, wipers, heater fan, cigarette lighter, etc.). Of the items you mentioned, three are switched power (key on only) and one is unswitched (key on and/or off). Also, Mopar bulkhead connectors are notorious for having issues. A good cleaning never hurts.
http://www.mymopar.com/downloads/1968/68BarracudaA.jpghttp://www.mymopar.com/downloads/1968/68BarracudaB.jpgKeep us posted. You'll find plenty of help on Moparts.
