I'm having a problem where anything inside the car that needs constant power is not working, headunit, central locking internal roof lights, antenna. The head lights and hazards work.

Now I could be wrong but shouldn't I just need a constant power and ground to get the memory working in the head unit, trip computer, lights, etc? The auto electrician the dealer used said the ACC power is not working on the ignition barrel.

Does this make sense to any one or am I getting the shaft?