Power Cord Is Broken

I have a Garmin StreetPilot C-330. The power cord is broken at the point where the wire reinforcement enters the bottom of the unit. It appears that most of the individual wires are still in tact, but there are some wire strands sticking out of the hole. When I power up, the unit says it can not locate any satellites (perhaps the wire strands?). Is a replacement cord available? Could a later model cord be a solution? How do I access the connections for the cord?