I had the same problem a couple of years ago. The power receptacle had become unplugged.
There is a special tool that reaches down into the receptacle which allows you to pull it right out, plug wiring and all. No need to go behind the dash. I pulled mine out, then reached in with a piece of bent coat hangar and fished out the plug and wiring through the hole. I didn't buy the tool, just made one from an old screwdriver. If you search around online for receptacles, you can find instructions on exactly how to do the removal and usually pictures of the tool involved.
Bill.