When fixing or changing a radio in a car, a wiring diagram will help make sure things are connected correctly. A wiring diagram for the radio of a 1990 Dodge Dakota can be found in its maintenance manual.
You can find a 1999 Chevrolet Corvette radio wiring diagram in a Corvette service manual. The service manual can be found at your local library. Most Chevrolet dealerships will provide the radio wiring diagram free.